Adjuvant Chemotherapy Does Not Compensate for an Inadequate Right Colon Cancer Surgery: High Peritoneal Recurrence Rates Indicate Need for Altered Treatment Paradigms.

There is a lack of evidence for optimal management of patients with right colon cancers upon referral to the oncology care centre, following an inadequate index surgery elsewhere. A prospectively maintained database of patients with right colon cancers managed between 2013 and 2019 was screened to identify those patients who underwent index surgery in a non-oncological setup. They were managed with adjuvant chemotherapy followed by observation, with surgery being reserved for recurrent disease. Of the 155 patients identified after the screening, 97 were included in the study. They were stratified depending upon the number of lymph nodes harvested at primary surgery-Group A (less than 12 nodes) (n = 49), Group B (12 to 27 nodes) (n = 39) and Group C (28 and more nodes) (n = 9). Patients with lymph node metastases had inferior survival at 2 years than node-negative patients and this survival difference increased progressively from Group A towards Group C. Patients who had radiological locoregional residual disease upon restaging (at presentation) had significantly inferior survival. At the end of 2 years, overall survival and disease-free survival of the cohort were 71.5% and 45.8%, respectively. Fifty-eight patients had disease relapse, with peritoneal recurrence seen in 37 patients (63.8%). Of these, only 15.5% recurrences were surgically salvageable. Treatment of patients who have undergone inadequate index colectomy with chemotherapy alone has shown inferior survival outcomes with high rates of peritoneal relapse in comparison to historical cohorts. The treatment strategy for such patients needs to be revisited in a prospective study design.