35 y/o man. Colonoscopy for rectal bleeding. Reported carcinoma at 25cm. Hiperplastic polyp in rectum
Histology: Moderate differentiate adenocarcinoma
Mother had colon cancer diagnosed at age 55. Mother had TAH + BSO aged 39 for endometrial cancer. Mothernal grandfather had colon cancer and “brain cancer” in his 40s.
Proband has two health younger siblings and no offspring.
PRE-OP REVIEW OF HISTOLOG
Crohn’s-like lymphoid respond
hHMLH1 Staining normal
hHMSH2 Staining absent
hHMSH6 Staining absent
On-table colonoscopy. Rectosigmoid cancer. Laparotomy otherwise normal. Conventional left hemicolectomy with staple colorectal anastomosis.
FACTORS AFFECTING SURGICAL DECISIONS
20% carriers will never develop CRC. Compliance with colonoscopy surveillance. Suspicion of carrier status at index surgery. Site of primary cancer. Presence of synchronous cancer.
HEMICOLECTOMY vs. SUBTOTAL COLECTOMY
Decision analysis model using 2 cohort studies:
10-year rates of metachronous cancer (16% vs. 4%)
CRC when detected at surveillance (32% A; 54% B; 14%C)
5 year survival rates (98% A; 80% B; 60% C)
Life expectancy gains in STC vs. Hemicolectomy:
2.3 years at age 27
1.0 year at age 47
0.3 year at age 67
De Vos tot Nederveen Cappel et al (2003) Gut 52: 1752-55
RISK OF METACRHOMOUS CANCER IN HNPCC
116 HNPCC patients with CRC
<5% underwent STC
24.2% developed metacrhonous cancer after segmental colectomy
Fitzgibbons et al (1987) Ann Surg 206: 289-95
RISK OF RECTAL CANCER AFTER SUBTOTAL COLECTOMY
71 patients with median 158 (range 38-232) months follow up
Risk of rectal cancer after STC was 3% every 3 years (12% at 12 years)
Rodrigues-Bigas et al (1997) Ann Surg 225(2): 202-7
HNPCC patients with colon cancer or more than one advanced adenoma should be offered colectomy + IRA or hemicolectomy + annual surveillance.
HNPCC patients with rectal cancer should be offered proctocolectomy + IPAA or anterior resection + annual surveillance.