Colon and Rectal Cancer Symptoms, Stages and Treatment
In this article
What Is Colorectal Cancer?
Colorectal cancer is a malignant disease that develops when the cells lining the inner surface of the colon or rectum multiply uncontrollably. Colon and rectal cancers are generally discussed together as "colorectal cancer" because they share an embryological origin, similar risk factors, and largely overlapping treatment approaches; however, rectal cancer also has important distinctive features in surgical technique and local treatment (radiotherapy), which are discussed separately in this guide. Colorectal cancer is one of the most common cancers worldwide, and the great majority develop through the gradual transformation of a benign polyp (adenoma) into a malignancy over years (the adenoma-carcinoma sequence) — explaining the unique power of regular screening to prevent the disease by removing a polyp before it becomes cancerous. In this guide, we discuss the causes, symptoms, screening and diagnostic methods, staging, current treatment options, and the diagnostic and treatment process in Turkey for colorectal cancer comprehensively and based on current literature.
The colon and rectum form the final part of the digestive system; they are responsible for reabsorbing water and electrolytes and for storing and eliminating stool. The great majority of colorectal cancers (over 95%) arise from glandular cells lining the bowel and are adenocarcinomas ; other subtypes, such as neuroendocrine tumors, squamous cell carcinoma, and gastrointestinal stromal tumors (GIST), are much rarer and outside the scope of this guide.
How Common Is Colorectal Cancer? (Current Statistics)
The report published by IARC on 8 July 2026 in CA: A Cancer Journal for Clinicians containing estimates for 2024, GLOBOCAN 2024 reports colon and rectal cancers as separate categories: approximately 1.206.011 new colon cancer cases (the 4th most common cancer) and 778.594 new rectal cancer cases (the 8th most common) occur worldwide each year. Considered together as "colorectal cancer," these groups represent the world's 3rd most common cancer and the 2nd most common cause of cancer death ; approximately 556.774 people die from colon cancer and 339.370 from rectal cancer each year. Incidence is approximately 1,46 times higher in men than in women.
According to the Türkiye country fact sheet published by IARC in July 2026 as part of the same GLOBOCAN 2024 publication cycle, approximately 21.172 new colorectal cancer cases are reported (12.463 men, 8.709 women) — making colorectal cancer Turkey's 3rd most common cancer after lung and breast cancer (9,0% of all cancers). Approximately 10.630 people die from colorectal cancer annually. The age-standardized incidence rate is 21,6 per 100.000, and the 5-year point prevalence (the number of people currently living with the disease) is reported as 63.009.
According to the American Cancer Society's "Cancer Statistics, 2026" report, published on 13 January 2026, the estimated number of new colorectal cancer cases in the US for 2026 is 158.850, and the estimated number of deaths is 55.230. The overall 5-year relative survival rate, based on the SEER database and the cohort of patients diagnosed between 2015-2021, is %65 (reflecting a marked improvement from approximately 50% in the middle of the 1970s). In the ACS's separate, more detailed "Colorectal Cancer Statistics, 2026" report, published every three years and released on 2 March 2026, the reported 5-year survival rates by stage (based on a cohort one year older) are as follows: for colon cancer, 91% for localized disease, 74% for regional spread, and 13% for distant metastases; for rectal cancer, 90% for localized disease, 74% for regional spread, and 18% for distant metastases.
One of the most striking findings highlighted in the ACS's "Colorectal Cancer Statistics, 2026" report (based on 2013-2022 data) is that colorectal cancer incidence in different age groups is moving in completely opposite directions : in the 20-49 age group, incidence is rising by approximately %3 per year, and in the 50-64 age group by approximately %0,4 , while in those aged 65 and older it is falling by approximately %2,5 per year (the overall decrease comes entirely from the decline in the older population). Death rates in patients under 50 have also increased by approximately 1% annually since 2004. The report emphasizes that 45% of new colorectal cancer diagnoses are in adults under 65 (compared with 27% in 1995). Of patients diagnosed under age 50, approximately 75% unfortunately present at an advanced stage (regional or distant metastatic disease). Rectal cancer incidence specifically also increased by approximately 1% per year during 2018-2022 and now accounts for 32% of all colorectal cancer cases (compared with 27% in the middle of the 2000s).
Risk Factors
Modifiable Risk Factors
- Red and processed meat consumption: High consumption of red meat (particularly processed meat — such as sausages, salami, and sucuk) increases risk; the World Health Organization has classified processed meat as "carcinogenic to humans" (Group 1).
- Obesity and physical inactivity: A high body mass index and low physical activity markedly increase risk.
- Smoking and alcohol use: Long-term smoking and excessive alcohol consumption are both independent risk factors.
- A low-fiber, high-fat diet: A consistent association has been demonstrated between Western dietary habits and colorectal cancer risk.
Nonmodifiable Risk Factors
- Age: Risk rises markedly after age 50; however, as discussed above, incidence at a young age is also increasing.
- A personal history of adenomatous polyps or colorectal cancer
- A first-degree relative with colorectal cancer or an advanced adenoma: This increases risk approximately 2-fold; risk rises further if more than one relative is affected.
- Chronic inflammatory bowel disease (Crohn disease, ulcerative colitis): Risk is markedly increased, particularly with long-standing (more than 8-10 years) and extensive disease; regular colonoscopic surveillance is recommended in these patients.
Hereditary Syndromes
It results from inherited mutations in DNA mismatch repair (MMR) genes (MLH1, MSH2, MSH6, PMS2); it is the most common hereditary colorectal cancer syndrome and accounts for approximately 2-4% of all colorectal cancers. Lifetime colorectal cancer risk can range from 10-80% (depending on the gene affected); risks of endometrial, ovarian, stomach, small bowel, and urinary tract cancers are also increased. Tumors in individuals with this syndrome show microsatellite instability (MSI-H), discussed separately below.
APC gene mutations inherited through the family cause this syndrome, characterized by hundreds or even thousands of adenomatous polyps in the large bowel. If untreated, colorectal cancer risk is almost 100%; therefore, prophylactic colectomy (removal of the large bowel) is generally recommended in diagnosed individuals at a young age, once polyp burden exceeds a certain threshold.
Other rarer hereditary syndromes include MUTYH-associated polyposis, Peutz-Jeghers syndrome and juvenile polyposis syndrome . People with a family history of colorectal cancer/polyps at a young age or in large numbers should be assessed for genetic counseling.
The Adenoma-Carcinoma Sequence: How Does Colorectal Cancer Develop?
The great majority of colorectal cancers begin as benign polyps in the bowel wall (most often adenomatous polyps) and become malignant over years (usually 10 years or longer) through gradual genetic changes. This process is called the adenoma-carcinoma sequence and provides the fundamental scientific basis for colorectal cancer screening: these polyps can be identified and removed during colonoscopy before they become cancerous. Some polyps ("serrated" polyps) can progress to cancer through a different, separate molecular pathway (usually associated with a BRAF mutation and CpG island methylation); their flat (sessile) structure can make these polyps harder to recognize during colonoscopy.
What Are the Symptoms?
Colorectal cancer generally causes no symptoms at an early stage — screening tests (discussed below) are therefore very important. Symptoms and signs that can appear as the disease progresses include:
- Changes in bowel habits (diarrhea, constipation, or changes in stool consistency) lasting more than a few days
- Blood in the stool (bright red or dark/black)
- Persistent abdominal pain, cramping, or gas pain
- A feeling that the bowel has not emptied completely
- Unexplained weight loss
- Weakness and fatigue
- Iron deficiency anemia (which may be the first sign, particularly in right-sided colon cancers, because of hidden/unnoticed bleeding)
- Thin/pencil-shaped stools
- A palpable abdominal mass
These symptoms can also occur in many benign conditions, such as hemorrhoids and irritable bowel syndrome. However, prompt assessment is important, particularly in people over 45 or when symptoms persist/worsen at any age — especially given the increasing incidence in younger people.
Screening (Early Detection)
The current US Preventive Services Task Force (USPSTF) guideline, published on 18 May 2021 and still valid as of 2026, lowered the starting age of 50 in the previous 2016 recommendation to 45 — the main rationale was modeling studies reflecting the increasing incidence trend in young adults discussed above. Recommended screening methods and intervals for average-risk adults aged 45-75 are:
- Colonoscopy: Every 10 years
- Fecal occult blood testing (FIT): Every year
- Stool DNA-FIT testing (for example, Cologuard): Every 1-3 years
- CT colonography: Every 5 years
- Flexible sigmoidoscopy: Every 5 years alone, or every 10 years together with annual FIT
Screening decisions should be individualized between ages 76-85, and screening is not recommended above age 85. All these recommendations concern "average-risk" individuals without personal/familial risk factors; screening begins much earlier and at more frequent intervals in people with hereditary syndromes or a strong family history.
According to the ACS's 2026 report, screening rates rose markedly in the 45-49 age group after the age threshold was lowered to 45 (between 2019-2023, colonoscopy rates increased by 43% and stool-based testing by more than 5-fold); however, overall screening participation in this age group remains only approximately %37 — indicating that a substantial opportunity remains unused.
In Turkey, the Ministry of Health runs a free national colorectal cancer screening program based on fecal occult blood testing (FIT) every 2 years through Cancer Early Diagnosis, Screening, and Education Centers (KETEM) for average-risk individuals aged 50-70 (extended to age 45 in some implementations); people with a positive test are referred for colonoscopy for further assessment. Alongside breast and cervical cancer, this is one of the few cancers with an organized national screening program in Turkey. If you are in a risk group or of screening age, applying to KETEM is recommended.
How Is the Diagnosis Made?
- Colonoscopy: This is the diagnostic gold standard; it allows direct visualization of a suspicious lesion and biopsy, and even removal of suitable polyps during the same session.
- Biopsy and pathological examination: Definitive diagnosis is made by pathological examination of the tissue sample.
- Staging imaging: Computed tomography (CT) of the abdomen/pelvis and chest is standard for detecting distant metastases (most commonly in the liver and lungs). In rectal cancer, additionally, pelvic magnetic resonance imaging (MRI) or endorectal ultrasonography is used to assess the tumor's depth in the bowel wall and involvement of surrounding lymph nodes — this plays a critical role in planning surgery and neoadjuvant treatment.
- Carcinoembryonic antigen (CEA): This tumor marker, measured at baseline when the diagnosis is made, is not used for diagnosis; however, it is valuable for monitoring treatment response and detecting recurrence early after surgery.
Molecular and Genetic Tests: the Basis of Treatment Decisions
Treatment selection in colorectal cancer, particularly metastatic disease, depends largely on the tumor's molecular characteristics. Guidelines therefore recommend the following tests in every patient diagnosed at an advanced stage:
Approximately 40-50% of tumors carry KRAS mutations and 3-5% carry NRAS mutations; their presence indicates that the anti-EGFR drugs described below (cetuximab, panitumumab) will be ineffective and should not be used. BRAF V600E mutations occur in approximately 8-10% of cases, are generally associated with a more aggressive course, and offer a specific targeted treatment option (discussed below).
Seen in approximately 4-5% of tumors in metastatic disease (this can reach 15% in early-stage disease), this feature indicates an inherited (Lynch syndrome) or acquired (sporadic) defect in DNA repair mechanisms and results in accumulation of a very high number of mutations in the tumor. MSI-H/dMMR tumors respond much more markedly to immunotherapy (discussed below) than other colorectal tumors; testing is therefore essential in every patient with metastatic disease.
It occurs in approximately 2-3% of tumors (somewhat more often in RAS wild-type tumors) and predicts response to the HER2-targeted therapies discussed below.
Tumors from the cecum through the first 2/3 of the transverse colon are classified as "right-sided," while those in the remaining transverse colon, descending colon, sigmoid colon, and rectum are "left-sided." This distinction reflects not only anatomy but also embryological origin, molecular profile (MSI-H, BRAF mutations, and serrated pathology are more common in right-sided tumors), and treatment response: even when RAS/RAF wild-type, right-sided tumors respond markedly less effectively to anti-EGFR therapies (cetuximab, panitumumab); current guidelines therefore recommend anti-EGFR treatment primarily for left-sided, RAS/RAF wild-type tumors.
Staging: the TNM System (AJCC 8th Edition)
Colorectal cancer is staged using the internationally accepted TNM system . T describes how deeply the tumor has spread into the layers of the bowel wall (mucosa, submucosa, muscularis propria, subserosa/pericolic tissue, and adjacent organs), N describes regional lymph node involvement, and M describes distant metastasis.
| Stage | Definition |
|---|---|
| Stage 0 | Tis (carcinoma in situ) — tumor confined to the mucosa, without progression into deeper bowel wall layers |
| Stage I | Tumor confined to the submucosa or muscularis propria, with no lymph node/distant metastases (T1-T2, N0, M0) |
| Stage II | Tumor extends beyond all bowel wall layers or reaches adjacent structures, but without lymph node involvement (T3-T4, N0, M0); subdivided into IIA/IIB/IIC |
| Stage III | Regional lymph node involvement, with no distant metastases (any T, N1-N2, M0); subdivided into IIIA/IIIB/IIIC |
| Stage IV | Distant organ metastases (any T, any N, M1); most commonly liver, lung, peritoneum |
Stage II disease contains subgroups with markedly different prognoses. The presence of one or more of the following is considered "high-risk Stage II" and affects the adjuvant chemotherapy decision: a T4 tumor, poor differentiation (a high-grade tumor — although this rule does not apply to MSI-H tumors), lymphovascular or perineural invasion, tumor at or close to the surgical margin, preoperative bowel obstruction/perforation, or removal of an inadequate number of lymph nodes (fewer than 12).
Treatment of Colon Cancer
Surgery
The main treatment for localized colon cancer is removal of the bowel segment containing the tumor and the regional lymph nodes (colectomy). These operations are now often performed laparoscopically.
Adjuvant (Postoperative) Chemotherapy
Adjuvant chemotherapy is not recommended; surgery alone is generally sufficient.
The benefit of adjuvant chemotherapy is limited in low-risk Stage II patients and it is not routinely recommended. If one or more of the high-risk features listed above is present, adjuvant chemotherapy is considered (usually single-agent capecitabine/5-FU or, in selected patients, a regimen including oxaliplatin). In MSI-H tumors, chemotherapy based on 5-FU alone has been shown not to provide benefit and may even cause harm — the adjuvant treatment decision therefore requires particular care in MSI-H Stage II patients.
In Stage III (lymph node-positive) patients, the standard approach is oxaliplatin-based adjuvant chemotherapy: FOLFOX (5-FU/leucovorin/oxaliplatin) or CAPOX/XELOX (capecitabine/oxaliplatin). The duration of this treatment, traditionally given for 6 months, was reassessed in a large analysis combining 6 trials from 6 countries, the IDEA collaboration: in low-risk patients (T1-3, N1), 3 months of CAPOX provides similar survival compared with 6 months, while carrying a markedly lower risk of cumulative neuropathy. In high-risk patients (T4 or N2), 6 months is still considered preferable. Current guidelines therefore recommend individualizing duration according to the patient's risk group and the regimen used (shortening duration is more safely achieved with CAPOX than with FOLFOX).
The Specific Treatment Approach in Rectal Cancer
The rectum requires a different treatment strategy from colon cancer because it lies in a narrow space in the pelvis, adjacent to the bladder and reproductive organs; local recurrence risk is higher, and local treatment (radiotherapy) therefore plays a much more central role.
Total Mesorectal Excision (TME)
This is the standard surgical technique for rectal cancer; it aims to remove the fatty tissue surrounding the rectum (the mesorectum), including its lymph nodes, intact as a whole and has markedly reduced local recurrence rates.
Neoadjuvant (Preoperative) Treatment
In locally advanced rectal cancer (T3-T4 or lymph node-positive), the current standard approach is to give all chemotherapy and chemoradiotherapy before surgery (TNT). This allows systemic chemotherapy, traditionally left until after surgery, to be given earlier to target micrometastases throughout the body more effectively; it has also been shown to increase complete pathological response rates.
Given the long-term side effects of radiotherapy in rectal cancer (bowel, bladder, and sexual dysfunction), PROSPECT answered an important question: in patients at intermediate risk who were suitable for sphincter-preserving surgery, preoperative FOLFOX chemotherapy alone (without radiotherapy) produced survival outcomes similar to standard chemoradiotherapy. By showing that radiotherapy could safely be omitted in selected patients, this finding provided important evidence for individualizing treatment.
In selected patients showing a complete clinical response (apparent complete disappearance of the tumor) on imaging and endoscopic assessment after neoadjuvant treatment, OPRA demonstrated that a "watch-and-wait" strategy — close follow-up rather than immediate surgery — could be safely used; a substantial proportion can continue long-term follow-up without surgery through this organ-preserving approach. However, it requires close, meticulous surveillance (regular imaging and endoscopy), with readiness for salvage surgery if recurrence occurs; it is not suitable for every patient and should be used at experienced centers following multidisciplinary assessment.
Treatment of Metastatic (Advanced) Colorectal Cancer
Treatment in patients with distant metastases is largely individualized according to the molecular test results described above. In selected patients with surgically resectable metastases confined to the liver or lungs, metastasectomy (surgical removal of metastases) can provide long-term disease-free survival or even cure; surgical feasibility must therefore be assessed in every patient with metastatic disease.
The First-Line Chemotherapy Backbone
For most patients without RAS/RAF mutations (wild-type) and without MSI-H, treatment uses a cytotoxic chemotherapy backbone (FOLFOX, FOLFIRI or, in selected patients with good performance status, the triplet regimen FOLFOXIRI) with the addition, according to the left/right-sided location and RAS/RAF status described above, of bevacizumab (anti-VEGF) or cetuximab/panitumumab (anti-EGFR).
Biomarker-Directed Treatments
In MSI-H/dMMR metastatic colorectal cancer, first-line pembrolizumab markedly prolonged progression-free survival and provided a higher response rate with less toxicity compared with standard chemotherapy. FDA approval: 2020.
On 8 April 2025, the FDA approved nivolumab+ipilimumab as first-line treatment for MSI-H/dMMR metastatic colorectal cancer based on CheckMate 8HW. Compared with chemotherapy, median progression-free survival was not reached (5,8 months with chemotherapy; HR 0,21), and the overall response rate was 71%; progression-free survival was also significantly superior compared with nivolumab alone (HR 0,62). This is an important advance reinforcing the immunotherapy-only (chemotherapy-free) approach in MSI-H/dMMR colorectal cancer.
BRAF V600E -mutant metastatic colorectal cancer was previously treated with encorafenib+cetuximab only in previously treated patients (second line and beyond), for whom it was approved; BREAKWATER brought the combination into the first-line setting: the FDA first granted accelerated approval on 20 December 2024 and then, based on maturing overall survival data, upgraded it to full approval on 24 February 2026 . This is the first regimen specifically approved for untreated BRAF V600E-mutant metastatic colorectal cancer. Encorafenib+cetuximab+chemotherapy (mFOLFOX6 or FOLFIRI) increased median overall survival, compared with standard chemotherapy ± bevacizumab, to 30,3 months versus 15,1 months (a 51% reduction in the risk of death), prolonged median progression-free survival to 12,8 months versus 7,1 months , and showed an overall response rate of 64% versus 39%. This is one of the most recent and striking developments in colorectal cancer treatment as of the date this guide was written (August 2026).
In previously treated patients with RAS wild-type, HER2-amplified metastatic colorectal cancer, trastuzumab+tucatinib received FDA approval (January 2023). The antibody-drug conjugate trastuzumab deruxtecan (Enhertu) also received tumor-agnostic accelerated approval on 5 April 2024 for HER2-positive (IHC 3+) advanced solid tumors (including colorectal cancer), based on DESTINY-CRC02; the colorectal cancer subgroup had a reported overall response rate of 46,9% and median duration of response of 5,5 months.
For the mutation found in a small proportion of all colorectal cancers (~3-4%), namely KRAS G12C , two different combinations have been approved for previously treated patients. Adagrasib+cetuximab received accelerated FDA approval on 21 June 2024. Sotorasib+panitumumab was approved on 16 January 2025 based on CodeBreaK 300; compared with standard treatment, it prolonged progression-free survival to 5,6 months versus 2,0 months (HR 0,48) and showed an overall response rate of 26% versus 0%. Both combinations are currently approved only in previously treated patients, not in the first-line setting.
Specific Approaches in Liver-Limited Metastatic Disease
In selected patients whose metastases are confined to the liver, in addition to surgical resection, experienced centers may consider hepatic arterial infusion (HAI) — which delivers high-dose chemotherapy directly into the hepatic artery feeding the tumor — or local methods such as ablation (radiofrequency/microwave); these approaches may also aim to make initially unresectable disease operable (conversion therapy).
Later-Line Treatments
| Drug / Trial | Conditions for Use | Main Result |
|---|---|---|
| Regorafenib (CORRECT) | Patients resistant/intolerant to standard treatments | Median overall survival 6,4 months versus 5,0 months (placebo), HR 0,77 |
| Trifluridine-tipiracil / TAS-102 (RECOURSE) | Patients resistant/intolerant to standard treatments, single agent | Median overall survival 7,1 months versus 5,3 months (placebo), HR 0,68 |
| Trifluridine-tipiracil + bevacizumab (SUNLIGHT) | The same patient group, with bevacizumab added | Median overall survival 10,8 months versus 7,5 months (single-agent TAS-102), HR 0,61 |
| Fruquintinib (FRESCO-2) | Heavily pretreated patients (after chemotherapy, anti-VEGF, anti-EGFR, and immunotherapy if applicable) | Median overall survival 7,4 months versus 4,8 months (placebo), HR 0,66 |
In STELLAR-303, zanzalintinib+atezolizumab improved overall survival compared with regorafenib in previously treated metastatic colorectal cancer. The FDA application was accepted on 2 February 2026, with 3 December 2026 targeted as the decision date. As of August 2026, the combination has not yet been approved; we recommend that our readers continue to follow this development.
Treatment Side Effects and Their Management
Standard Chemotherapy Drugs
Oxaliplatin characteristically causes cold-sensitive tingling in the hands/feet that worsens with cumulative dose, known as peripheral neuropathy ; this played an important role in the treatment-duration decision (the IDEA trial described above). Irinotecan can cause acute (within the first 24 hours, preventable with atropine) and delayed (appearing a few days later, treated with loperamide) forms of marked diarrhea ; toxicity risk is higher in patients with certain variants in the UGT1A1 gene. 5-Fluorouracil (5-FU) and capecitabine can cause hand-foot syndrome (particularly with capecitabine), diarrhea, mucositis, and rare but potentially serious cardiac toxicity (coronary vasospasm); severe toxicity risk is markedly increased in patients with DPD enzyme deficiency.
Anti-VEGF and Anti-EGFR Drugs
Bevacizumab carries risks of hypertension, proteinuria, bleeding, and rare but potentially serious bowel perforation; it must be stopped for a specified period before planned surgery. Cetuximab and panitumumab characteristically cause an acneiform skin rash (on the face and trunk), inflammation around the nails (paronychia), and low magnesium levels; rash severity may correlate positively with drug response and is therefore also considered an important clinical clue when deciding whether to continue treatment.
Immunotherapy Drugs
Checkpoint inhibitors such as pembrolizumab, nivolumab, and ipilimumab may cause "immune-related adverse events" (irAEs) due to excessive immune activation: colitis, hepatitis, pneumonitis, endocrine disorders, and skin reactions. These side effects may be more frequent and severe with ipilimumab-containing combinations than with single agents; management is based on severity grading.
Diagnosis, Licensing, and Reimbursement in Turkey
Colorectal cancer diagnosis and treatment in Turkey are carried out in general surgery, gastroenterology, and oncology centers at university and training/research hospitals, in line with international guidelines. For drugs to be used in Turkey, TİTCK licensing is required first; for SGK coverage, a separate reimbursement decision under SUT is also necessary.
Standard chemotherapy drugs (5-FU, capecitabine, oxaliplatin, irinotecan) have long been licensed and routinely covered by SGK. Bevacizumab is covered by SGK subject to specific regimen and treatment-line conditions (provided bevacizumab has not previously been used). Cetuximab and panitumumab are covered by SGK in RAS wild-type patients only with FOLFOX or FOLFIRI (one chosen, until progression), limited to the 1st or 2nd line; patients must be anti-EGFR-naive, and anti-EGFR reuse after progression is not permitted. Regorafenib is covered by SGK provided all previous standard treatment lines (fluorouracil, oxaliplatin, irinotecan, and anti-VEGF/anti-EGFR where appropriate) have been exhausted.
According to our sources, trifluridine-tipiracil (Lonsurf) is licensed in Turkey but has no clearly defined place in the standard SGK reimbursement list; there are indications that patients generally obtain access through individual applications/legal action. Pembrolizumab has no clearly verified SGK coverage for the MSI-H/dMMR colorectal cancer indication. Nivolumab is, according to our sources, covered by SGK for MSI-H/dMMR colorectal cancer only as a second-line single agent ; no record was found of nivolumab+ipilimumab (CheckMate 8HW, first line) being licensed/covered in Turkey — consistent with the recent FDA approval (April 2025). Encorafenib is licensed in Turkey (primarily for the melanoma indication), but SGK coverage for its colorectal cancer combination could not be verified. Trastuzumab deruxtecan is licensed in Turkey, but reimbursement for its colorectal cancer indication is unclear. Sotorasib is licensed in Turkey (for lung cancer), but according to our sources is not covered by SGK; the status of its colorectal cancer combination also could not be verified.
According to our sources, fruquintinib (Fruzaqla), tucatinib and adagrasib have no TİTCK license in Turkey.
Drug licensing and reimbursement status can change frequently with SUT updates; the Turkish status of new combinations approved in 2024-2026 (such as BREAKWATER, CheckMate 8HW, and CodeBreaK 300) in particular may become clearer or change over time. The information in this section is a general summary compiled as of the date this article was updated (August 2026); always confirm precise, current information about your own treatment and reimbursement with your treating physician and the latest SGK SUT text.
Frequently Asked Questions
- If a polyp is removed during colonoscopy, am I protected from cancer?
- Removing adenomatous polyps during colonoscopy largely eliminates the chance that these polyps will progress to cancer — the main reason screening is one of the few methods that can "prevent" cancer. However, because the risk of developing new polyps remains, repeat colonoscopy at the recommended intervals is necessary.
- I am under 45 with no family history of colorectal cancer; should I still take my symptoms seriously?
- Yes. Colorectal cancer incidence in young adults is rising, and it is generally diagnosed at a more advanced stage in this group — partly because symptoms are often attributed to benign causes such as hemorrhoids. Persistent changes in bowel habits or rectal bleeding should be assessed at any age.
- Does every patient with metastatic colorectal cancer receive the same treatment?
- No. Treatment is individualized according to many factors, including RAS/RAF mutation status, MSI/dMMR and HER2 status, tumor location in the colon (right/left side), and the patient's overall health. Comprehensive molecular testing is therefore important in every patient with metastatic disease.
- Is a permanent stoma (bag) always necessary in rectal cancer?
- No. Depending on tumor location and size, sphincter (anal muscle)-preserving surgery is now possible in most patients with rectal cancer; some may receive a temporary stoma to protect postoperative healing. The need for a permanent stoma depends on factors such as the tumor's proximity to the anus and is assessed by the surgeon before surgery.
- Sung H, et al. "Global cancer statistics 2024." CA: A Cancer Journal for Clinicians, 2026. DOI: 10.3322/caac.70090
- IARC Global Cancer Observatory (GLOBOCAN 2024) — Colon and Rectum Cancer Fact Sheets, Turkey Country Fact Sheet. gco.iarc.who.int
- Siegel RL, et al. "Cancer Statistics, 2026." CA: A Cancer Journal for Clinicians, 2026. DOI: 10.3322/caac.70043
- Siegel RL, et al. "Colorectal Cancer Statistics, 2026." CA: A Cancer Journal for Clinicians, 2026. DOI: 10.3322/caac.70067
- US Preventive Services Task Force. "Colorectal Cancer: Screening" (current guideline dated 18 May 2021). uspreventiveservicestaskforce.org
- Grothey A, et al. IDEA Collaboration — adjuvant treatment duration (3 months versus 6 months). NEJM, 2018.
- Schrag D, et al. "PROSPECT: Neoadjuvant Chemotherapy without Routine Radiation for Rectal Cancer." NEJM, 2023.
- Garcia-Aguilar J, et al. "OPRA: Organ Preservation in Rectal Adenocarcinoma." J Clin Oncol, 2022 and subsequent follow-up data.
- André T, et al. "Pembrolizumab in MSI-H Metastatic Colorectal Cancer" (KEYNOTE-177). NEJM, 2020.
- FDA approval announcement: Nivolumab + Ipilimumab, first-line MSI-H/dMMR mCRC (CheckMate 8HW), 8 April 2025. fda.gov
- Kopetz S, et al. "Encorafenib, Cetuximab, and Chemotherapy" (BREAKWATER), accelerated approval data, 2024; full approval/overall survival analysis, 2026.
- Strickler JH, et al. "Tucatinib and Trastuzumab" (MOUNTAINEER), HER2+ mCRC. Lancet Oncology, 2023.
- FDA approval announcement: Trastuzumab deruxtecan, HER2+ solid tumors (including DESTINY-CRC02 data), 5 April 2024. fda.gov
- Yaeger R, et al. "Adagrasib with Cetuximab" (KRYSTAL-1), KRAS G12C mCRC, accelerated approval, June 2024.
- FDA approval announcement: Sotorasib + Panitumumab (CodeBreaK 300), KRAS G12C mCRC, 16 January 2025. fda.gov
- Grothey A, et al. "Regorafenib" (CORRECT). Lancet, 2013.
- Mayer RJ, et al. "Trifluridine-Tipiracil" (RECOURSE). NEJM, 2015.
- Prager GW, et al. "Trifluridine-Tipiracil plus Bevacizumab" (SUNLIGHT). NEJM, 2023.
- Dasari A, et al. "Fruquintinib" (FRESCO-2). Lancet, 2023.
- Republic of Turkey Ministry of Health — KETEM Colorectal Cancer Screening Program.
- Communiqué Amending the Healthcare Implementation Communiqué, 10 July 2025 (SGK SUT update).
Was this article helpful?
Your feedback helps us improve our content.
