Colorectal Cancer

Colorectal cancer is prevented by colonoscopic polypectomy, cured in its early stages by surgery, and managed with combination chemotherapy, targeted therapy, and immunotherapy in advanced stages.

 

Our five-step approach at Shree Hospitals begins before cancer develops - with screening colonoscopy to detect and remove precancerous polyps - and extends through complete staging, surgical management, adjuvant therapy coordination, and lifelong surveillance after treatment.

 

Step 1 - Screening Colonoscopy and Polyp Detection

 

Over 95% of colorectal cancers develop from adenomatous polyps - benign precancerous growths on the bowel mucosa - through the adenoma-carcinoma sequence over 5–10 years.

 

Colonoscopy detects these polyps and removes them by polypectomy before they transform into invasive cancer. This is the definitive preventive strategy: the one intervention that breaks the cancer development sequence before cancer begins.

 

We recommend colonoscopy screening from age 45 for average-risk individuals (no symptoms, no family history); from age 40 or 10 years before the youngest affected first-degree relative's age of diagnosis for patients with a family history of CRC; and from diagnosis of IBD onset for long-standing extensive UC patients.

 

Lynch syndrome - the most common hereditary CRC syndrome, caused by germline mutations in DNA mismatch repair genes (MLH1, MSH2, MSH6, PMS2) - requires colonoscopy every 1–2 years from age 20–25.

 

Step 2 - Diagnostic Workup and Staging

 

Confirmed colorectal cancer on biopsy is staged before treatment to determine operability and systemic spread. TNM staging classifies by: T (tumour - T1 invasion through mucosa/submucosa to T4 invasion through bowel wall into adjacent organs), N (lymph node involvement - N0 negative to N2 four or more positive regional lymph nodes), and M (metastasis - M0 no distant disease, M1 liver, lung, peritoneal, or distant lymph node metastasis).

 

The staging workup at Shree Hospitals includes: contrast-enhanced CT chest, abdomen, and pelvis for systemic staging; MRI pelvis for rectal cancer local staging (mesorectal fascia clearance, relationship to sphincters, lymph node assessment); CEA (carcinoembryonic antigen) as a baseline prognostic marker and post-treatment surveillance tool; and MSI/MMR status testing (mismatch repair protein immunohistochemistry on the biopsy) - because MMR-deficient (MSI-high) CRC predicts response to immunotherapy and identifies Lynch syndrome candidates for genetic counselling.

 

Step 3 - Surgical Resection

 

Surgery is the curative modality for non-metastatic colorectal cancer. Laparoscopic right hemicolectomy (right colon cancers), left hemicolectomy or sigmoid colectomy (left colon and sigmoid), and laparoscopic low anterior resection (LAR) with total mesorectal excision (TME) for rectal cancer are performed at Shree Hospitals with equivalent oncological outcomes to open surgery and significantly faster recovery.

 

For very low rectal cancers involving the anal sphincter, abdominoperineal resection (APR) with permanent sigmoid colostomy is required when sphincter-sparing surgery is not anatomically feasible.

 

Laparoscopic surgery allows 3–4-day hospital stays, earlier return to normal activity, and lower wound complication rates. Neoadjuvant chemoradiotherapy - radiotherapy combined with capecitabine before surgery - is the standard of care for T3/T4 or node-positive rectal cancers to downstage the tumour, reduce local recurrence, and maximise the probability of sphincter preservation.

 

Step 4 - Adjuvant and Palliative Chemotherapy

 

Stage III colon cancer (node-positive) and selected high-risk Stage II patients receive adjuvant chemotherapy after surgery to eliminate micrometastatic disease and reduce recurrence risk.

 

Standard adjuvant regimen: CAPOX (capecitabine + oxaliplatin, 8 cycles over 6 months) or FOLFOX (infusional 5-FU + leucovorin + oxaliplatin, 12 cycles over 6 months).

 

Stage IV disease (metastatic CRC) is treated with systemic chemotherapy - FOLFOX or FOLFIRI (5-FU + leucovorin + irinotecan) - combined with targeted therapy: bevacizumab (anti-VEGF, targeting tumour angiogenesis) or anti-EGFR agents (cetuximab, panitumumab) exclusively in RAS wild-type tumours.

 

MMR-deficient/MSI-high metastatic CRC responds dramatically to immune checkpoint inhibitors - pembrolizumab (anti-PD-1) produces durable responses that conventional chemotherapy cannot achieve in this molecular subtype.

 

Step 5 - Surveillance After Treatment

 

After curative-intent colorectal cancer treatment, structured surveillance is essential for early detection of recurrence and metachronous polyp development.

 

We follow international guidelines: CEA every 3–6 months for the first 3 years then 6-monthly to 5 years; CT chest, abdomen, pelvis every 6–12 months for 3 years; colonoscopy at 1 year post-surgery (to detect missed synchronous lesions or anastomotic recurrence), then every 3–5 years if normal.

 

Liver metastases detected on surveillance CT that were not present at initial staging are assessed for resectability - hepatic metastatectomy in patients with isolated, resectable liver metastases achieves 30–40% five-year survival, converting Stage IV disease to potentially curable with surgery.