Molecular classification of patients with malignant melanoma for new therapeutic strategies

BRAF/NRAS Mutation Frequencies Among Primary Tumors and Metastases in Patients With Melanoma

Purpose

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.

Patients and Methods

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.

Results

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.

Conclusion

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.

Melanoma: a model for testing new agents in combination therapies

Treatment for both early and advanced melanoma has changed little since the introduction of interferon and IL-2 in the early 1990s. Recent data from trials testing targeted agents or immune modulators suggest the promise of new strategies to treat patients with advanced melanoma. These include a new generation of B-RAF inhibitors with greater selectivity for the mutant protein, c-Kit inhibitors, anti-angiogenesis agents, the immune modulators anti-CTLA4, anti-PD-1, and anti-CD40, and adoptive cellular therapies. The high success rate of mutant B-RAF and c-Kit inhibitors relies on the selection of patients with corresponding mutations. However, although response rates with small molecule inhibitors are high, most are not durable. Moreover, for a large subset of patients, reliable predictive biomarkers especially for immunologic modulators have not yet been identified. Progress may also depend on identifying additional molecular targets, which in turn depends upon a better understanding of the mechanisms leading to response or resistance. More challenging but equally important will be understanding how to optimize the treatment of individual patients using these active agents sequentially or in combination with each other, with other experimental treatment, or with traditional anticancer modalities such as chemotherapy, radiation, or surgery. Compared to the standard approach of developing new single agents for licensing in advanced disease, the identification and validation of patient specific and multi-modality treatments will require increased involvement by several stakeholders in designing trials aimed at identifying, even in early stages of drug development, the most effective way to use molecularly guided approaches to treat tumors as they evolve over time.

Role of Anthracyclines in the Treatment of Early Breast Cancer

Purpose

To review data relating to anthracyclines in the adjuvant treatment of early breast cancer.

Design

This is a report from a seminar in which the future of anthracyclines in the adjuvant treatment of breast cancer was considered. In particular, the question of whether anthracyclines should now be discarded and replaced by taxanes was addressed.

Results

Accumulating data from large randomized trials indicate that genetic markers may have a role in predicting sensitivity to cytotoxic drugs. However, no reliable, validated test is available for predicting sensitivity to anthracyclines in particular. Topoisomerase IIα amplification and/or deletion, especially in conjunction with human epidermal growth factor receptor-2 amplification, has been proposed to fulfill this role but more data are needed. Currently, only one published trial has shown that a taxane-based regimen may be superior to an anthracycline-based regimen, but several trials indicate that combinations including both anthracyclines and taxanes may be better still. Further studies aimed at optimizing anthracyclines and taxanes in combination, and integrating biologic agents, seem to be the way forward. There is no validated test that can determine whether anthracyclines can be of greater benefit than other agents for individual patients.

Conclusion

Anthracyclines have been extensively tested in clinical trials spanning several decades; currently, there are insufficient data to recommend replacing them in the adjuvant treatment of breast cancer.

Pooled Analysis of Individual Patient-Level Data From All Randomized, Double-Blind, Placebo-Controlled Trials of Darbepoetin Alfa in the Treatment of Patients With Chemotherapy-Induced Anemia

Purpose

Although numerous clinical trials have demonstrated the efficacy and tolerability of erythropoiesis-stimulating agents (ESAs) in patients with chemotherapy-induced anemia (CIA), results of some recent trials and one meta-analysis have suggested that ESAs may negatively impact survival and/or disease control in patients with cancer.

Methods

To assess the benefits and risks of ESAs in CIA, we conducted a pooled analysis of individual patient-level data from all randomized, double-blind, placebo-controlled trials in 2,122 patients with CIA receiving darbepoetin alfa (DA; n = 1,200) or placebo (n = 912).

Results

DA did not increase mortality (hazard ratio = 0.97; 95% CI, 0.85 to 1.1) and had no effect on progression-free survival (hazard ratio = 0.93; 95% CI, 0.84 to 1.04) and disease progression (hazard ratio = 0.92; 95% CI, 0.82 to 1.03), but, as expected, increased the risk for thromboembolic events (hazard ratio = 1.57; 95% CI, 1.10 to 2.26). Overall and progression-free survival were not affected by baseline hemoglobin and seemed better in patients who achieved hemoglobin more than 12 or more than 13 g/dL. Transfusions and rates of hemoglobin increase (> 1 g/dL in 14 days; > 2 g/dL in 28 days) owing to transfusions were associated with an increased risk for death and disease progression in both treatment groups; in the absence of transfusions, rates of hemoglobin increase did not appear to increase the risk for adverse outcomes. Compared with placebo, DA significantly reduced the risk of receiving one or more transfusion.

Conclusion

There seemed to be no association between DA and risk of death or disease progression in this meta-analysis of individual patient data from DA studies conducted in CIA, the approved indication for ESAs in oncology.

Adjuvant therapy of melanoma with interferon: lessons of the past decade

The effect of interferon alpha (IFNalpha2) given alone or in combination has been widely explored in clinical trials over the past 30 years. Despite the number of adjuvant studies that have been conducted, controversy remains in the oncology community regarding the role of this treatment. Recently an individual patient data (IPD) meta-analysis at longer follow-up was reported, showing a statistically significant benefit for IFN in relation to relapse-free survival, without any difference according to dosage (p = 0.2) or duration of IFN therapy (p = 0.5). Most interestingly, there was a statistically significant benefit of IFN upon overall survival (OS) that translates into an absolute benefit of at least 3% (CI 1-5%) at 5 years. Thus, both the individual trials and this meta-analysis provide evidence that adjuvant IFNalpha2 significantly reduces the risk of relapse and mortality of high-risk melanoma, albeit with a relatively small absolute improvement in survival in the overall population. We have surveyed the international literature from the meta-analysis (2006) to summarize and assimilate current biological evidence that indicates a potent impact of this molecule upon the tumor microenvironment and STAT signaling, as well as the immunological polarization of the tumor tissue in vivo. In conclusion, we argue that there is a compelling rationale for new research upon IFN, especially in the adjuvant setting where the most pronounced effects of this agent have been discovered. These efforts have already shed light upon the immunological and proinflammatory predictors of therapeutic benefit from this agent--that may allow practitioners to determine which patients may benefit from IFN therapy, and approaches that may enable us to overcome resistance or enhance the efficacy of IFN. Future efforts may well build toward patient-oriented therapy based upon the knowledge of the unique molecular features of this disease and the immune system of each melanoma patient.

Short preoperative treatment with erlotinib inhibits tumor cell proliferation in hormone receptor-positive breast cancers

PURPOSE

To administer the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib to patients with operable untreated breast cancer during the immediate preoperative period and to measure an antiproliferative and/or a proapoptotic effect in the post-therapy specimen and determine a biomarker profile associated with evidence of erlotinib-mediated cellular activity.

PATIENTS AND METHODS

Newly diagnosed patients with stages I to IIIA invasive breast cancer were treated with erlotinib 150 mg/d orally for 6 to 14 days until the day before surgery. Erlotinib plasma levels were measured by tandem mass spectrometry the day of surgery. Drug-induced changes in tumor cell proliferation and apoptosis were assessed by Ki67 immunohistochemistry and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling analysis, respectively, in biopsies from the pretherapy and surgical specimens. Biopsies were also evaluated for P-EGFR, P-HER-2, P-MAPK, P-Akt, P-S6, and S118 P-ER alpha.

RESULTS

In drug-sensitive PC9 xenografts, 5 days of treatment with erlotinib were enough to induce a maximal inhibition of cell proliferation and induction of apoptosis. Forty-one patients completed preoperative treatment with erlotinib. Grade <or= 2 rash and diarrhea were the main toxicities. Erlotinib inhibited tumor cell proliferation (Ki67), P-EGFR, and P-HER-2. The inhibition of proliferation occurred in estrogen receptor (ER) -positive but not in human epidermal growth factor receptor 2 (HER-2) -positive or triple-negative cancers. Treatment was associated with a significant reduction of P-MAPK, P-Akt, P-S6, and S118 P-ER alpha in hormone receptor-positive cancers.

CONCLUSION

A presurgical approach to evaluate cellular responses to new drugs is feasible in breast cancer. EGFR inhibitors are worthy of testing against ER-positive breast cancers but are unlikely to have clinical activity against HER-2-positive or triple-negative breast cancers.