Pre-treatment metastatic growth rate is associated with clinical outcome in patients with metastatic renal cell carcinoma treated with nivolumab.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have been approved for the treatment of metastatic renal cell carcinoma (mRCC). However, the response rate is still limited, and it is urgent to pursue novel and concise markers of responses to ICIs that allow the determination of clinical benefits. Recently, it was reported that the metastatic growth rate (MGR) is an independent factor associated with clinical outcome for anticancer therapy in some types of cancer. METHODS: We investigated pre-treatment MGR before starting nivolumab for mRCC patients between September 2016 to October 2019. In addition, we examined clinicopathological factors including MGR and analyzed the correlation between pre-treatment MGR and clinical efficacy of nivolumab. RESULTS: Of all patients, the median age was 63 years (range, 42-81), and the median observation period was 13.6 months (range, 1.7-40.3). Twenty-three patients and sixteen patients were classified as the low and the high MGR group, respectively, with the cutoff value of 2.2 mm/month. Progression-free survival (PFS) and overall survival (OS) were significantly better in patients in the low MGR group (p = 0.005 and p = 0.01). Importantly, in multivariate analysis, only the high MGR was significantly associated with a decrease of PFS (Hazard ratio (HR): 2.69, p = 0.03) and OS (HR: 5.27, p = 0.02). CONCLUSIONS: Pre-treatment MGR may serve as the simple and valid indicator obtained from imaging studies, and the prominent surrogate marker associated with OS and PFS in mRCC patients treated with nivolumab.

Baseline metastatic growth rate is an independent prognostic marker in patients with advanced BRAF V600 mutated melanoma receiving targeted therapy.

BACKGROUND: Targeted therapy (TT) of BRAF V600 mutated unresectable melanoma with inhibitors of the MAPK pathway achieves response rates of up to 76%, but most patients develop secondary resistance. Albeit TT is strikingly efficacious during the first days of treatment, even in advanced cases, long-term survival is highly unlikely, especially in patients with unfavorable baseline characteristics like elevated lactate dehydrogenase (LDH). In patients treated with anti-PD-1 immune checkpoint inhibitors, elevated baseline metastatic growth rate (MGR) was the most important prognostic factor. Here, we aimed at investigating the prognostic impact of MGR in patients with unresectable melanoma receiving TT. METHODS: Clinical records of 242 patients with at least one measurable target lesion (TL) receiving TT at seven skin cancer centers were reviewed. Baseline MGR was determined measuring the largest TL at baseline and at one earlier timepoint. RESULTS: Overall survival (OS) and progression-free survival (PFS) were significantly impaired in patients with an MGR > 3.9 mm/month (median OS: 11.4 vs. 35.5 months, P < 0.0001; median PFS: 4.8 vs. 9.2 months, P < 0.0001). Multivariable analysis of OS and PFS revealed that the prognostic impact of elevated MGR was independent of LDH, presence of brain and liver metastases, tumor burden, and line of treatment. The prognostic significance of elevated MGR was highest in patients with normal LDH. CONCLUSIONS: Baseline MGR is an important independent prognostic marker for OS and PFS in melanoma patients treated with TT. Its implementation in clinical routine is easy and could facilitate the prognostic stratification.