Clinical factors and overall survival (OS) associated with patterns of metastases (mets) in melanoma patients (pts)

Abstract

Background: Specific anatomical locations of melanoma mets (MM) influence OS in pts treated with anti-PD-1 based immunotherapy (IT), but little is known about anatomical distribution of mets within a patient (patterns of MM). We investigated the clinical factors and OS associated with the patterns of MM. Methods: Demographics, disease characteristics and patient outcomes were examined fromMMpts. Univariate and multivariable (MVA) logistic regression was used to identify factors associated with patterns of MM. Cox proportional hazards method for OS analysis. Results: 6031MMpts were studied; median age of 61yo, 66% male, 32% elevated LDH, 74% stage IV M1c/d. 17% had systemic treatment; IT (61%), targeted therapy (32%) and chemotherapy (7%) 1st line. Median FU was 57.5 months (mos) and the median OS (mOS) was 9.4 mos (untreated: 7.5 mos; treated: 39.4 mos). InMVA performed on untreated pts, elevated LDH (HR 1.5) and presence of brain (HR 1.5), liver (HR 1.8) and bone (HR 1.5) mets were associated with shorter OS; while gastrointestinal (GI) mets (HR 0.8) were associated with longer OS. Similar results were found for treated pts; but male pts had shorter OS (HR 1.3) and GI mets did not affect OS. Within all pts, mOS for pts with vs without brain mets was 8 vs 10 mos (p<0.01), respectively; and mOS for pts with vs without liver mets was 7 vs 11 mos (p<0.01), respectively. In untreated pts, brain mets were associated with adrenal mets, but not liver, GI, bone or subcutaneous (subcut); while in treated pts brain mets were associated with adrenal and subcut mets. Liver mets occurred frequently with bone, adrenal and spleen mets, and less frequently with brain, GI and subcut mets in untreated pts; while they were associated with bone and spleen mets in treated pts. Untreated pts with brain, liver or bone mets had longer mOS in the presence of GI mets (7 vs 11; 6 vs 8; 7 vs 11mos, respectively), while GI mets did not affect OS in treated pts. Treated pts with liver mets have shorter OS (22 mos) if bone (18 mos), adrenal (14 mos) or spleen (18 mos) mets are present, but this was not seen in untreated pts. Conclusions: Both treated and untreated pts have distinct patterns ofMMand survival. These data may help defining prognosis and provides insight to further studies on the biology of mets.