Fowler, Graham

BackgroundThe significance of tumor‐infiltrating lymphocytes (TILs) in melanoma is debated. This article presents a multicenter, retrospective study assessing the predictive and prognostic value of TILs.MethodsThe Sentinel Lymph Node Working Group database was queried from 1993 to 2018 for cases with known TIL data. TILs were categorized as absent or present, which included nonbrisk (NB), brisk (B), and present but unspecified TIL levels. Clinicopathologic factors were correlated with TILs, sentinel lymph node (SLN) status, and melanoma‐specific survival (MSS).ResultsOverall, 3203 patients were included. The median thickness was 1.5 mm, and 469 cases had SLN metastases. TILs were present in 2458 cases (76.7%), with NB, B, and unspecified TILs seen in 1691 (68.8%), 691 (28.1%), and 76 (3.1%), respectively. Multivariable analysis showed that the presence of TILs significantly predicted a negative SLN biopsy (P < .05). The median follow‐up was 25.2 months. MSS was significantly better for cases with TILs than cases without TILs (P < .001). According to multivariable analysis, age, gender, thickness, mitotic rate, ulceration, lymphovascular invasion, and SLN status were significantly prognostic of MSS (all P values < .05). Although TILs were not prognostic of MSS, when multiple imputation was used and the SLN status was excluded, the presence of TILs was significantly prognostic of improved MSS (hazard ratio, 0.78; 95% confidence interval, 0.64‐0.95; P = .0154).ConclusionsTILs are a favorable marker because their presence significantly predicts a negative SLN, and the absence of TILs may be a prognostic marker of worse survival in patients with a positive SLN but not a negative SLN. TILs may also serve as a prognostic marker of survival when the SLN status is not considered.

AbstractBackground and ObjectivesThe prognostic significance of regression in predicting melanoma recurrences is unknown. We present a large multicenter study correlating regression with recurrence.MethodsThe Sentinel Lymph Node Working Group database was queried from 1993 to 2018 for cases with regression data. Clinicopathologic factors were correlated with overall and first‐site of recurrence and with recurrence‐free survival (RFS).ResultsThere were 4790 patients and the median follow‐up was 39.6 months. Regression and recurrences were seen in 1081 (22.6%) and 773 (16.1%) cases, respectively. First‐site locoregional and distant recurrences were seen in 412 (8.6%) and 352 (7.3%) patients, respectively. Regression was seen in 15.8% and 24.7% of all cases with and without recurrences (p < 0.0001), respectively, while regression was seen in 14.3% and 17.9% of first‐site locoregional and distant recurrent cases, respectively, compared with 23.3% and 22.9% of patients with regression and without first‐site locoregional and distant recurrences, respectively (p = 0.29). On multivariable analysis, after controlling for age, gender, thickness, ulceration, lymphovascular invasion, and sentinel lymph node status, regression significantly predicted improved RFS (p = 0.004) and fewer first‐site regional recurrences (p = 0.017).ConclusionOur data suggest that regression is a favorable prognostic marker in melanoma and predicts significantly better RFS and decreased first‐site regional recurrences.