Melanoma of unknown primary: experience at Massachusetts General Hospital and Dana-Farber Cancer Institute

Abstract

Melanoma may present metastatically without an identifiable primary lesion. To further characterize the epidemiology of melanoma of unknown primary (MUP), we report our experience with a cohort of MUP patients. We retrospectively reviewed patients seen at the Massachusetts General Hospital (MGH) and the Dana-Farber Cancer Institute (DFCI) between 1986 and 1996 with follow-up to 2002. Data were analysed using log-rank and proportional hazards analyses, with death from any cause as the main outcome measure. Of the 2485 melanoma patients seen, 65 (2.6%) had MUP; 41 patients were male [63.1%; 95% confidence interval (CI), 50.2%, 74.7%]. The median age at diagnosis was 54.1 years (interquartile range, 39.4-67.1 years). Thirty patients had lymph node metastases, 12 cutaneous or subcutaneous metastases and 23 visceral metastases. Of the 62 patients (95.4%) with at least some follow-up, there were 42 deaths from any cause. Patients with lymph node metastases survived significantly longer than patients with other metastases [5-year survival 38.7% (95% CI, 18.1%, 59.1%) vs. 13.9% (95% CI, 4.4%, 28.6%); P<0.01]. After adjusting for stage and age at diagnosis, there was some evidence that men survived longer than women [hazard ratio (HR)=0.55; 95% CI, 0.28, 1.09]. Survival did not differ amongst patients with different types of non-lymph node metastases. The 5-year survival rates in this cohort did not differ from those of historical controls with known primaries. The demographic and survival characteristics of this MUP cohort mirrored those found in previous studies. More studies of MUP patients, as well as a standardized definition of MUP, may shed light on the pathogenesis and prognosis of MUP.

Improved survival for stage IV melanoma from an unknown primary site

“…9 3,7,13 However, some 6,10 seem to indicate higher survivals for MUP patients compared to reported survivals from larger stage IV studies.…”

“…Some studies report a guarded prognosis, 9,12 while others demonstrate a more favorable survival for stage IV disease from MUP versus melanoma from a known primary (MKP; Table 1). 4,6 We previously reported a favorable outcome after regional lymphadenectomy for clinical stage III melanoma from MUP versus MKP. 15 We hypothesized that if this survival advantage reflects an immunologic response to melanoma, then it should apply to patients with distant metastasis from MUP.…”

Lung metastasis of malignant melanoma with unknown primary origin

“…Malignant melanoma cases with unknown primary origin are rarely seen, constituting 2-6% of all malignant melanoma cases (3)(4)(5). In the study conducted by de Waal et al (4), the primary origin was reported to be unknown in 857 (2.6%) of 33,181 melanoma patients monitored between 2003 and 2009.…”

Cáncer de piel: Una realidad cotidianamente ignorada.

“…Prevención secundaria (46,47,48,49,50,51) Las fotografías secuenciales son básicas para el seguimiento de nevos sospechosos en los individuos con gran número de nevos y nevos displaśicos.…”