Obstructed colon cancer: Review and perspectives.

Obstructed colon cancer (OCC) accounts for approximately 25% of colorectal cancer at the time of diagnosis and represents a surgical emergency creating a dual challenge: (i) the management of an acute mechanical colonic obstruction with potentially life-threatening consequences (fluid and electrolyte disturbances, systemic deterioration, colonic ischemia, stercoral stasis); and (ii) the treatment of an advanced primary or metastatic malignancy, often in elderly or frail patients with significant comorbidities. For right-sided OCC, right hemicolectomy with or without ileocolic anastomosis is the recommended approach, while a primary diverting ileostomy as a bridge to delayed right colectomy may be considered a safe alternative. For left-sided OCC, a diverting colostomy allows for subsequent oncological colectomy following complete disease staging and patient optimization. Hartmann's procedure should be reserved for perforated OCC, whereas (sub)total colectomy is indicated in cases of proximal colonic ischemia. In the setting of ischemia or perforation of a markedly distended proximal colon, a bowel-preserving (or colonic-sparing) strategy consisting of ileocecal resection with ileocolostomy - temporarily leaving the primary tumor in situ - may represent an alternative to (sub)total colectomy. Colonic stenting can be considered as an alternative to diverting colostomy in experienced centers. Given the poor prognosis of OCC and the high morbidity of emergency surgery - which may delay or even preclude adjuvant chemotherapy - novel treatment strategies are warranted. These include the use of neoadjuvant chemotherapy during the interval between creation of a diverting stoma (ileostomy or colostomy) or colonic stent placement and subsequent elective colectomy, regardless of the primary tumor location.