Algorithm for detection of small-bowel metastasis in malignant melanoma of the skin

The aim of this study was to develop an algorithm to detect small-bowel metastasis (SBM) of melanoma by sequential laboratory parameters and pan-intestinal endoscopy (PIE) including video capsule endoscopy (VCE).

A total of 390 melanoma patients (AJCC stage I/II/III/IV, 140/80/121/49) were screened for signs of intestinal blood loss (fecal occult blood test [FOBT] or overt bleeding) in an open, multicenter, prospective study, and those who were positive underwent PIE. Independent of the presence of intestinal bleeding, all stage IV patients were offered PIE. Follow-up was obtained in 357 patients (91.5 %) for a median of 16 months. We undertook to identify possible associations between SBM and clinical and laboratory data. Survival data were analyzed with regard to clinical and laboratory data and small-bowel findings.

Intestinal blood loss was suspected in 49 of 390 patients (12.6 %), 38 of whom (77.6 %) agreed to undergo endoscopy. In 10 patients, SBM was detected by VCE (intention-to-diagnose, 20.4 %; AJCC III, n = 2; AJCC IV, n = 8). The SBM was resected in five patients. Total detection rates of SBM were 14 of 49 patients in stage IV (28.6 %, intention-to-diagnose), 2 of 121 in stage III (1.7 %), and 0 in stage I/II. In FOBT-positive patients, SBM detection rates were 72.7 %, 14.3 %, and 0 % in tumor stages IV, III, and I/II, respectively. Positive FOBT proved to be an independent negative prognostic factor for total survival in stage III and IV melanoma.

SBMs are frequent in advanced melanoma. In stage III patients, screening for intestinal blood loss by PIE may help to identify SBMs. In stage IV, indication for PIE should depend on the individual consequences of detecting SBM, but not on bleeding symptoms alone.