Is chemotherapy mandatory after surgery for colon cancer?

The vast majority of patients will undergo surgery first for colon cancer if the tumor has not spread to other parts of the body. This is done with the intent to cure. After around a week, the histopathology (biopsy) report is in. Usually, by this time, the patient is discharged and doing well. The question is whether chemotherapy is required or whether observation with regular check-ups is enough. The basic rule of thumb is that chemotherapy is suggested if the chances of tumor recurrence are relatively high, based on scientific evidence.

Cutting to the chase, most patients in India will require chemotherapy since the stage at which the cancer is detected is usually relatively advanced. Very early-stage tumors are mainly detected on routine colonoscopy (general check-up without symptoms), so they are incidentally diagnosed. Once a patient develops significant symptoms, it is usually at a stage that requires chemotherapy.

Specifically, patients with symptoms of significant obstruction (extreme difficulty or inability to pass stool) or severe bleeding should receive chemotherapy. Patients in which the tumor has penetrated the wall of the colon or if lymph nodes are involved will require chemotherapy. Poorly differentiated tumors should also be considered for chemotherapy. If the report reveals stage 2 disease (pT3N0) with no other poor prognostic features, an MSI (Microsatellite Instability

y test) is advised. This helps in the decision about the benefit of adjuvant chemotherapy.

In short, there are instances when chemotherapy may not be required, but it is uncommon. Chemotherapy may not be advised if the tumor stage is very early, with minimal symptoms. Another reason for not advising chemotherapy is if the patient’s general condition is unfit to tolerate chemotherapy.

To conclude, your oncologist is the best person to decide on treatment options in consultation with a multidisciplinary tumor board. Organ-based disease management clinical groups ensure the best possible outcomes for patients.