Outcomes after en bloc resection with sacrectomy of advanced colorectal carcinomas that invade the sacrum: a multiinstitutional descriptive series.

Objective: Management of locally invasive colorectal carcinoma at any stage currently involves surgical excision followed by chemoradiotherapy; however, the prognosis is poor, with a 5-year overall survival (OS) of only 5%. Failure to achieve gross-total resection is associated with poorer OS, and patients with residual tumor postresection (R1 or R2 resection) have a median OS of 7 months compared with 23 months in those who undergo resection with negative margins (R0 resection). For tumors that have invaded the sacrum, sacrectomy becomes necessary to achieve R0 resection. The objective of this study was to provide a descriptive multicenter account of resection for locally invasive colorectal carcinoma with sacral invasion, focusing on the association of tumor morphometry with surgical planning and perioperative outcomes.

Methods: Demographic, comorbidity, clinical, tumor-specific, operative characteristic, and outcome data were collected on all patients who underwent resection of colorectal carcinoma with concurrent sacral resection between January 2005 and May 2022. Patients were grouped into those having undergone surgery for purely palliative intent, or those with resection with attempt at local control and dichotomized into level of osteotomy (either proximal or distal to the S2-3 level).

Results: Twenty-two patients (median age 50.5 [IQR 43.3-60.0] years, 54.5% female) underwent sacrectomy for colorectal carcinoma. Operative records indicated intent for local control in 14 patients and palliative in the remaining 8 patients. Palliative surgical intent was based primarily on the presence of distant metastases. There was no significant difference in median local progression-free survival between patients undergoing osteotomy proximal to the S2-3 level and those undergoing osteotomy distal to the S2-3 level.

Conclusions: En bloc resection is believed to offer the best local control in patients with locally invasive colorectal carcinoma. The present descriptive series highlights outcomes of en bloc resection with partial or full sacrectomy in patients with tumors showing local extension into the sacrum. Complications are common, most often in the form of wound dehiscence or infection, and many patients require placement in a rehabilitation or intermediate-care facility upon discharge. However, for those with stage III (locally aggressive) disease, median OS exceeds 16 years, suggesting that such aggressive management with en bloc resection may be warranted in properly selected patients.