The role of BRAF V600 mutation in melanoma Ascierto, Paolo A; Kirkwood, John M; Grob, Jean-Jacques ...
Journal of translational medicine,
05/2012, Volume:
10, Issue:
1
Journal Article
Peer reviewed
Open access
BRAF is a serine/threonine protein kinase activating the MAP kinase/ERK-signaling pathway. About 50 % of melanomas harbors activating BRAF mutations (over 90 % V600E). BRAFV600E has been implicated ...in different mechanisms underlying melanomagenesis, most of which due to the deregulated activation of the downstream MEK/ERK effectors. The first selective inhibitor of mutant BRAF, vemurafenib, after highly encouraging results of the phase I and II trial, was compared to dacarbazine in a phase III trial in treatment-naïve patients (BRIM-3). The study results showed a relative reduction of 63 % in risk of death and 74 % in risk of tumor progression. Considering all trials so far completed, median overall survival reached approximately 16 months for vemurafenib compared to less than 10 months for dacarbazine treatment. Vemurafenib has been extensively tested on melanoma patients expressing the BRAFV600E mutated form; it has been demonstrated to be also effective in inhibiting melanomas carrying the V600K mutation. In 2011, both FDA and EMA therefore approved vemurafenib for metastatic melanoma carrying BRAFV600 mutations. Some findings suggest that continuation of vemurafenib treatment is potentially beneficial after local therapy in a subset of patients with disease progression (PD). Among who continued vemurafenib >30 days after local therapy of PD lesion(s), a median overall survival was not reached, with a median follow-up of 15.5 months from initiation of BRAF inhibitor therapy. For patients who did not continue treatment, median overall survival from the time of disease progression was 1.4 months. A clinical phase I/II trial is evaluating the safety, tolerability and efficacy of vemurafenib in combination with the CTLA-4 inhibitor mAb ipilimumab. In the BRIM-7 trial vemurafenib is tested in association with GDC-0973, a potent and highly selective inhibitor of MEK1/2. Preliminary data seem to indicate that an additional inhibitor of mutated BRAF, GSK2118436, might be also active on a wider range of BRAF mutations (V600E-K-D-R); actually, treatment with such a compound is under evaluation in a phase III study among stage III-IV melanoma patients positive for BRAF mutations. Overall, BRAF inhibitors were well tolerated; common adverse events are arthralgia, rash, fatigue, alopecia, keratoacanthoma or cutaneous squamous-cell carcinoma, photosensitivity, nausea, and diarrhea, with some variants between different inhibitors.
The prevalence of BRAF, NRAS, and p16CDKN2A mutations during melanoma progression remains inconclusive. We investigated the prevalence and distribution of mutations in these genes in different ...melanoma tissues.
In all, 291 tumor tissues from 132 patients with melanoma were screened. Paired samples of primary melanomas (n = 102) and synchronous or asynchronous metastases from the same patients (n = 165) were included. Tissue samples underwent mutation analysis (automated DNA sequencing). Secondary lesions included lymph nodes (n = 84), and skin (n = 36), visceral (n = 25), and brain (n = 44) sites.
BRAF/NRAS mutations were identified in 58% of primary melanomas (43% BRAF; 15% NRAS); 62% in lymph nodes, 61% subcutaneous, 56% visceral, and 70% in brain sites. Mutations were observed in 63% of metastases (48% BRAF; 15% NRAS), a nonsignificant increase in mutation frequency after progression from primary melanoma. Of the paired samples, lymph nodes (93% consistency) and visceral metastases (96% consistency) presented a highly similar distribution of BRAF/NRAS mutations versus primary melanomas, with a significantly less consistent pattern in brain (80%) and skin metastases (75%). This suggests that independent subclones are generated in some patients. p16CDKN2A mutations were identified in 7% and 14% of primary melanomas and metastases, with a low consistency (31%) between secondary and primary tumor samples.
In the era of targeted therapies, assessment of the spectrum and distribution of alterations in molecular targets among patients with melanoma is needed. Our findings about the prevalence of BRAF/NRAS/p16CDKN2A mutations in paired tumor lesions from patients with melanoma may be useful in the management of this disease.
Cancer radiotherapy (RT) may induce what is referred to as the "abscopal effect," a regression of non-irradiated metastatic lesions distant from the primary tumor site directly subject to ...irradiation. This clinical response is rare, but has been surmised to be an immune-mediated phenomenon, suggesting that immunotherapy and RT could potentially synergize. Here, we report the outcome of patients with advanced melanoma treated with the immune checkpoint blockade monoclonal antibody antagonist, ipilimumab followed by RT. Patients were selected for enrollment at the National Cancer Institute "Fondazione G.Pascale" through the expanded access program in Italy. Those who experienced disease progression after ipilimumab thus received subsequent RT and were selected for analysis. Among 21 patients, 13 patients (62%) received RT to treat metastases in the brain and 8 received RT directed at extracranial sites. An abscopal response was observed in 11 patients (52%), 9 of whom had partial responses (43%) and 2 had stable disease (10%). The median time from RT to an abscopal response was 1 month (range 1-4). Median overall survival (OS) for all 21 patients was 13 months (range 6-26). Median OS for patients with abscopal responses was extended to 22.4 months (range 2.5-50.3) vs. 8.3 months (range 7.6-9.0) without. A local response to RT was detected in 13 patients (62%) and, of these, 11 patients (85%) had an abscopal response and abscopal effects were only observed among patients exhibiting a local response. These results suggest RT after ipilimumab may lead to abscopal responses in some patients with advanced melanoma correlating with prolonged OS. Our data also suggest that local responses to RT may be predictive of abscopal responses. Further research in larger randomized trials is needed to validate these results.
Indications for sentinel lymph node biopsy (SLNB) for thin melanoma are continually evolving. We present a large multi-institutional study to determine factors predictive of sentinel lymph node (SLN) ...metastasis in thin melanoma.
Retrospective review of the Sentinel Lymph Node Working Group database from 1994 to 2012 identified 1,250 patients who had an SLNB and thin melanomas (≤ 1 mm). Clinicopathologic characteristics were correlated with SLN status and outcome.
SLN metastases were detected in 65 (5.2%) of 1,250 patients. On univariable analysis, rates of Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, ulceration, and absence of regression differed significantly between positive and negative SLN groups (all P < .05). These four variables and mitotic rate were used in multivariable analysis, which demonstrated that Breslow thickness ≥ 0.75 mm (P = .03), Clark level ≥ IV (P = .05), and ulceration (P = .01) significantly predicted SLN metastasis with 6.3%, 7.0%, and 11.6% of the patients with these respective characteristics having SLN disease. Melanomas < 0.75 mm had positive SLN rates of < 5% regardless of Clark level and ulceration status. Median follow-up was 2.6 years. Melanoma-specific survival was significantly worse for patients with positive versus negative SLNs (P = .001).
Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, and ulceration significantly predict SLN disease in thin melanoma. Most SLN metastases (86.2%) occur in melanomas ≥ 0.75 mm, with 6.3% of these patients having SLN disease, whereas in melanomas < 0.75 mm, SLN metastasis rates are < 5%. By using a 5% metastasis risk threshold, SLNB is indicated for melanomas ≥ 0.75 mm, but further study is needed to define indications for SLNB in melanomas < 0.75 mm.
Background
The relationship between tumor-infiltrating lymphocytes (TILs) and regression in melanoma is unknown. This report describes a large multicenter study assessing the association between TILs ...and regression.
Methods
The Sentinel Lymph Node Working Group database was queried from 1993 to 2018 for cases with TILs and regression data. Clinicopathologic factors were correlated with regression and TIL status, sentinel lymph node (SLN) status, and overall survival (OS).
Results
The study enrolled 2450 patients. In 1811 cases, TILs (73.9%) were present, with regression present in 328 of these 1811 (18.1%) cases and in 49 (7.7%) of 639 cases without TILs. The presence of TILs was significantly associated with regression (
p
< 0.0001) as well as a negative SLN (
p
< 0.05). However, when TILs were stratified by regression status, only absence or presence of both TILs and regression were significantly associated with SLN metastases (
p
= 0.038). Although the presence of TILs was associated with OS (
p
< 0.05), regression status by itself was not (
p
= 0.2058 and 0.252, respectively). Furthermore, when TILs were stratified by regression status, only the presence of TILs with or without regression was significantly associated with improved OS (
p
= 0.0081 and 0.0137, respectively) versus the absence of both TILs and regression, with regression status not significantly affecting OS for patients with or without TILs (
p
= 0.2314 and 0.65, respectively).
Conclusions
Regression is highly correlated with TILs, but only TILs are significantly associated with SLN metastasis and OS in melanoma patients, whereas regression is not. The impact of regression on outcomes ultimately appears dependent upon the absence or presence of TILs.
Background
Sentinel lymph node biopsy (SLNB) is recommended for intermediate thickness melanoma, but for thick melanoma, guidelines are less definitive about the use of SLNB in this population. We ...present a study on thick melanoma evaluating for prognostic factors.
Patients and Methods
The Sentinel Lymph Node Working Group database was queried for thick (> 4 mm) melanoma cases that had a SLNB from 1993 to 2018. Clinicopathologic characteristics were correlated with SLN status and melanoma-specific survival (MSS).
Results
There were 1235 patients. Median follow-up was 28 months. Median thickness was 5.9 mm, with 956, 175, and 104 cases presenting thickness > 4–8, > 8–12, and > 12 mm, respectively. SLN metastases were seen in 439 of 1235 (35.5%) cases and in 33.9%, 40.6%, and 42.3% of melanomas > 4–8, > 8–12, and > 12 mm, respectively. In each thickness group, MSS was significantly worse for SLN-positive compared with SLN-negative cases (all
P
< 0.005). Multivariable analysis showed that SLN metastasis, male gender, increasing thickness, lymphovascular invasion, and microsatellitosis significantly predicted worse MSS for melanomas > 4–8 mm, with SLN metastasis showing the greatest risk (HR 2.17, 95% CI 1.64–2.87,
P
< 0.0001). For melanomas > 8 mm, only SLN metastasis significantly predicted MSS (> 8–12 mm: HR 3.93, 95% CI 2.00–7.73,
P
< 0.0001; > 12 mm: HR 3.58, 95% CI 1.56–8.22,
p
< 0.0027).
Conclusions
Thick melanoma patients with SLN metastasis have significantly worse MSS compared with SLN-negative patients, even in the thickest cases, and SLN status is the most powerful and/or only predictor of MSS. Given these results, SLNB shows important prognostic value in this population and is indicated for clinically localized thick melanoma.
Ipilimumab and vemurafenib have both been shown to improve survival in phase III trials of patients with metastatic melanoma. Although vemurafenib is associated with a rapid onset of activity, ...responses are often of limited duration. Conversely, responses to ipilimumab take time to develop, but can be durable. Currently, limited data exist on the sequencing of these agents in patients with the BRAFV600 mutation. The aim of this analysis was to identify factors that could potentially be used to optimise the order in which ipilimumab and BRAF inhibitors are administered in this patient population.
This was a retrospective, single-institution, analysis of patients treated with vemurafenib 960 mg or dabrafenib 150 mg twice-daily and ipilimumab 3 mg/kg every 3 weeks for 4 doses as part of a clinical trial or expanded access program. Eligible patients tested positive for the BRAFV600 mutation and had sequentially received treatment with vemurafenib or dabrafenib followed by ipilimumab, or vice versa.
In total, 34 BRAF-mutation positive patients were eligible, comprising six patients who received ipilimumab followed by a BRAF inhibitor, and 28 patients treated with a BRAF inhibitor who subsequently received ipilimumab. Of these 28 patients, 12 (43%) had rapid disease progression resulting in death and were unable to complete ipilimumab treatment as per protocol. These patients were classified as having rapid disease progression. Median overall survival for rapid progressors was 5.7 months (95% CI: 5.0-6.3), compared with 18.6 months (95% CI: 3.2-41.3; p < 0.0001) for those patients who were able to complete ipilimumab treatment. Baseline factors associated with rapid progression were elevated lactate dehydrogenase, a performance status of 1 and the presence of brain metastases. Patients were more likely to have rapid disease progression if they had at least two of these risk factors at baseline.
Our analysis suggests it may be possible to identify those patients at high risk of rapid disease progression upon relapse with a BRAF inhibitor who might not have time to subsequently complete ipilimumab treatment. We hypothesise that these BRAF-mutation positive patients may benefit from being treated with ipilimumab first.
Background
Complete lymph node dissection, the current standard treatment for nodal metastasis in melanoma, carries the risk of significant morbidity. Clinically apparent nodal tumor is likely to ...impact both preoperative lymphatic function and extent of soft tissue dissection required to clear the basin. We hypothesized that early dissection would be associated with less morbidity than delayed dissection at the time of clinical recurrence.
Materials and Methods
The Multicenter Selective Lymphadenectomy Trial I randomized patients to wide excision of a primary melanoma with or without sentinel lymph node biopsy. Immediate completion lymph node dissection (early CLND) was performed when indicated in the SLN arm, while therapeutic dissection (delayed CLND) was performed at the time of clinical recurrence in the wide excision-alone arm. Acute and chronic morbidities were prospectively monitored.
Results
Early CLND was performed in 225 patients, and in the wide excision-alone arm 132 have undergone delayed CLND. The 2 groups were similar for primary tumor features, body mass index, basin location, and demographics except age, which were higher for delayed CLND. The number of nodes evaluated and the number of positive nodes was greater for delayed CLND. There was no significant difference in acute morbidity, but lymphedema was significantly higher in the delayed CLND group (20.4% vs. 12.4%,
P
= .04). Length of inpatient hospitalization was also longer for delayed CLND.
Conclusion
Immediate nodal treatment provides critical prognostic information and a likely therapeutic effect for those patients with nodal involvement. These data show that early CLND is also less likely to result in lymphedema.
PDF
