Differential influence of vemurafenib and dabrafenib on patients' lymphocytes despite similar clinical efficacy in melanoma.

BACKGROUND: Since the majority of melanomas eventually become resistant and progress, combining selective BRAF inhibitors (BRAFi) with immunotherapies has been proposed to achieve more durable treatment responses. Here, we explored the impact of selective BRAFi on the hosts' immune system. PATIENTS AND METHODS: Clinical data, whole blood counts (WBC) and serum lactate dehydrogenase (LDH) of 277 vemurafenib- and 65 dabrafenib-treated melanoma patients were evaluated. The frequency and phenotype of lymphocyte subpopulations were determined by flow cytometry while T cell cytokine secretion was measured by multiplex assays. RESULTS: Progression-free survival (PFS) as well as overall survival (OS) were similar in patients treated with either BRAFi. High pretreatment LDH was associated with shorter PFS and OS in both groups. During therapy, peripheral lymphocytes decreased by 24.3% (median, P < 0.0001) in vemurafenib-treated patients but remained unchanged in dabrafenib-treated patients (+1.2%, P = 0.717). Differentiation of peripheral lymphocytes of vemurafenib-treated patients showed a significant decrease in CD4(+) T cells (P < 0.05). Within CD4(+) T cells obtained during treatment, an increase in CCR7(+)CD45RA(+) (naïve) and a decrease in CCR7(+)CD45RA(-) (central memory) populations were found (P < 0.01 for both). Furthermore, secretion of interferon-γ and interleukin-9 by CD4(+) T cells was significantly lower in samples obtained during vemurafenib treatment compared with baseline samples. CONCLUSION: While both compounds have comparable clinical efficacy, vemurafenib but not dabrafenib decreases patients peripheral lymphocyte counts and alters CD4(+) T cell phenotype and function. Thus, selective BRAFi can significantly affect patients' peripheral lymphocyte populations. Fully understanding these effects could be critical for successfully implementing combinatorial therapies of BRAFi with immunomodulatory agents.

The volume of postoperative drainage fluid as a potential early predictor of lymphedema after lymph node excision for metastatic melanoma.

Lymphedema (LE) following lymph node dissection is a major problem for cancer patients, and radiation therapy, extended surgery, groin dissection, obesity, and older age are well-established risk factors of LE. We studied whether these risk factors are further associated with high volumes of postoperative drainage fluid after complete lymph node dissection (CLND) for melanoma metastases. Moreover, we examined whether a high amount of drainage fluid after sentinel lymph node biopsy (SLNB) can predict a high amount of drainage fluid after subsequent CLND. Using descriptive statistics and regression analyses, we analyzed the cumulative volumes of postoperative drainage fluid for 836 melanoma patients with lymph node excision in the axilla or groin. In multiple regression analyses, the well-established risk factors of LE, i.e., increased body mass index, older age, and ilioinguinal versus inguinal versus axillary dissection predicted a high drainage volume after CLND. Of note, a high drainage fluid volume after SLNB also predicted a high drainage volume after subsequent CLND. In patients with groin dissections, who are particularly susceptible to swelling, extended iliac dissection, age above 60, and a cumulative drainage volume of more than 100 ml in the preceding SLNB were predictors of the cumulative drainage volume. We find that common risk factors predict the volume of postoperative drainage fluid after CLND and postoperative LE. Further, high postoperative drainage volume may therefore function as a potential early predictor of LE following CLND.

[Multilocular pyoderma gangrenosum after uterus resection]. / Multilokuläres Pyoderma gangraenosum nach Uterusresektion.

A 71-year-old patient presented with very painful ulcers after uterus-resection with the da Vinci® Surgical System 3 months before. The anamnesis revealed that in the past 10 months similar wounds had appeared after osteosynthesis of a humerus fracture and after breast biopsy. The patient had been unsuccessfully treated with different antibiotics and wound dressings for several months for a suspected superinfected, postoperative disturbed wound healing. None of the wounds became smaller or healed completely. After exclusion of relevant differential diagnoses pyoderma gangrenosum (PG) could be diagnosed and systemic immunosuppressive therapy was initiated. The pain improved rapidly and complete wound healing was achieved. Pyoderma gangrenosum is a rarely diagnosed autoimmune disease which often occurs after physical trauma such as surgical interventions. Because a correct diagnose is usually made late it is important to be aware of this disease to treat it early and correctly.