What is the treatment approach for ovarian cancer (Ca ovary) involving the sigmoid colon with luminal narrowing?

Treatment Approach for Ovarian Cancer Involving the Sigmoid Colon with Luminal Narrowing

Surgical resection with en bloc removal of the sigmoid colon is the recommended treatment for ovarian cancer involving the sigmoid colon with luminal narrowing, aiming for complete tumor debulking with no residual disease.

Rationale for Surgical Approach

The management of ovarian cancer with sigmoid colon involvement requires an aggressive surgical approach focused on optimal cytoreduction, as the volume of residual tumor after surgery is one of the most significant prognostic factors for survival.

Primary Surgical Considerations:

1. Complete Tumor Debulking:

   • Maximal cytoreduction to less than 1 cm residual disease (optimal cytoreduction) doubles median survival from 17 to 39 months 1
   • Each 10% increase in cytoreduction is associated with a 5.5% increase in median survival 1
   • Patients with no macroscopic residual disease have significantly better outcomes with 2-year survival rates of 100% compared to 77.3% for <1 cm residual disease 2

2. En Bloc Resection:

   • When ovarian cancer invades neighboring organs like the sigmoid colon, resection should be performed en bloc 1
   • Rectosigmoid resection is the most common bowel operation in primary ovarian cancer surgery, performed in approximately 65% of cases requiring bowel surgery 3

Preoperative Preparation

1. Imaging and Assessment:

   • CT abdomen and pelvis with IV contrast to evaluate metastatic disease extent and plan surgical intervention 4
   • Transvaginal and transabdominal ultrasound to characterize the mass 4

2. Bowel Preparation:

   • Standard bowel preparation including washout with hypertonic solution
   • Low-residue diet
   • Intravenous broad-spectrum antibiotics
   • Marking of potential stoma sites 1

3. Referral Considerations:

   • Immediate referral to a gynecologic oncologist is crucial - this is the second most important prognostic factor after stage 4

Surgical Procedure

1. Standard Components:

   • Bilateral salpingo-oophorectomy
   • Total hysterectomy with vaginal closure
   • Complete infragastric omentectomy
   • Appendectomy 4

2. Sigmoid Colon Management:

   • For luminal narrowing due to tumor invasion, partial sigmoid colectomy with primary anastomosis is preferred 3
   • If rectosigmoid resection is necessary, a low colorectal anastomosis should be fashioned whenever possible 1
   • Temporary diverting colostomy may be considered in high-risk anastomoses
   • Permanent colostomy should be avoided when possible (78% of patients can avoid permanent colostomy) 5

3. Additional Procedures:

   • Pelvic and para-aortic lymphadenectomy if optimal cytoreduction is achieved 1
   • Peritoneal metastases excision
   • Other organ resection as needed for complete tumor removal 1

Special Considerations

1. Suboptimal Initial Surgery:

   • If initial surgery at a non-specialist center resulted in suboptimal resection:
     • Immediate reoperation by a gynecologic oncologist, OR
     • 2-3 courses of chemotherapy followed by interval debulking surgery 1

2. Extensive Disease:

   • For patients with extensive disease where optimal debulking seems unlikely:
     • Consider limited exploration (laparotomy or laparoscopy) for staging and biopsy
     • Proceed with 2-3 courses of neoadjuvant chemotherapy
     • Follow with interval debulking surgery 1
   • Note: Survival outcomes are better with primary complete tumor resection (5-year survival 62.2%) compared to resection after neoadjuvant chemotherapy (5-year survival 13.9%) 6

Postoperative Management

1. Chemotherapy:

   • Platinum-based chemotherapy regimens following optimal cytoreduction
   • Typically 6 cycles of treatment 2

2. Monitoring:

   • Careful monitoring for complications, particularly:
     • Febrile morbidity (occurs in 29% of cases)
     • Anastomotic leak (rare, <1% requiring reoperation) 3

Prognostic Factors

The most significant factors affecting survival and recurrence-free interval are:

1. Residual disease - most strongly predictive factor for recurrence or death
2. Depth of tumor infiltration of the bowel wall
3. Disease stage 2

Potential Complications

Despite multiple surgical procedures being performed in conjunction with sigmoid colectomy:

• 75% of patients have no significant postoperative morbidity
• Postoperative mortality is approximately 2.5% 5
• Febrile morbidity is the most common complication (29%) 3

Sigmoid colectomy as part of ovarian cancer debulking provides significant palliation of symptoms from large pelvic tumors but must be used judiciously in selected patients to achieve optimal outcomes 5.