Mucosal melanoma stage, site predict patient survival
Tumour stage and anatomic site significantly affect the prognosis of mucosal melanomas, while patient demographics and tumour thickness do not, a recent study has found.
Accessing the California Cancer Registry, researchers analysed 132,751 melanoma cases, of which 1.4 percent (n=1,824) were of mucosal melanoma. Majority of the cases (98.6 percent; n=130,927) were cutaneous in nature. The 5-year survival estimate was significantly lower for mucosal vs cutaneous melanoma patients (27.64 percent vs 76.28 percent).
Regardless of cancer type, stage at diagnosis was also a significant predictor of survival. Five-year estimates were worse for those with remotely (13.50 percent) and regionally (50.85 percent) metastasized cutaneous melanoma, as opposed to those with only localized metastases (82.87 percent).
The same pattern was true for mucosal melanoma patients (localized: 43.93 percent; regional: 18.76 percent; remote: 7.84 percent). Notably, 5-year survival estimates for localized mucosal melanoma was lower than cutaneous melanoma with regional metastasis.
The anatomic tumour site likewise emerged as a significant prognostic factor. Five-year survival estimates for the genitourinary, oral cavity, nasal and sinus, gastrointestinal, and anorectal malignancies were 37.41 percent, 27.85 percent, 23.77 percent, 20.94 percent and 16.68 percent, respectively. The estimate for melanomas occurring in other sites was 13.57 percent.
Multivariate Cox proportional hazards regression analysis further confirmed that stage at diagnosis was a significant predictor of survival in both cutaneous (distant vs local metastasis: hazard ratio [HR], 7.64, 95 percent CI, 7.37–7.92) and mucosal (HR, 3.36, 2.9–3.92) melanomas.
Similarly, mucosal melanomas occurring at less common primary sites (spine, lung and pleura, liver, and pancreas: HR, 1.93, 1.41–2.64) also posed an increased risk of death, as did oral, anorectal and gastrointestinal mucosal melanomas.