Circulating tumor DNA to monitor treatment response and detect acquired resistance in patients with metastatic melanoma

Repeat tumor biopsies to study genomic changes during therapy are difficult, invasive and data are confounded by tumoral heterogeneity. The analysis of circulating tumor DNA (ctDNA) can provide a non-invasive approach to assess prognosis and the genetic evolution of tumors in response to therapy. Mutation-specific droplet digital PCR was used to measure plasma concentrations of oncogenic BRAF and NRAS variants in 48 patients with advanced metastatic melanoma prior to treatment with targeted therapies (vemurafenib, dabrafenib or dabrafenib/trametinib combination) or immunotherapies (ipilimumab, nivolumab or pembrolizumab). Baseline ctDNA levels were evaluated relative to treatment response and progression-free survival (PFS). Tumor-associated ctDNA was detected in the plasma of 35/48 (73%) patients prior to treatment and lower ctDNA levels at this time point were significantly associated with response to treatment and prolonged PFS, irrespective of therapy type. Levels of ctDNA decreased significantly in patients treated with MAPK inhibitors (p < 0.001) in accordance with response to therapy, but this was not apparent in patients receiving immunotherapies. We show that circulating NRAS mutations, known to confer resistance to BRAF inhibitors, were detected in 3 of 7 (43%) patients progressing on kinase inhibitor therapy. Significantly, ctDNA rebound and circulating mutant NRAS preceded radiological detection of progressive disease. Our data demonstrate that ctDNA is a useful biomarker of response to kinase inhibitor therapy and can be used to monitor tumor evolution and detect the early appearance of resistance effectors.     

High-dose tamoxifen added to concurrent biochemotherapy with decrescendo interleukin-2 in patients with metastatic melanoma

BACKGROUND: In vitro cell culture data and preclinical models suggest that tamoxifen modulates tumor cell sensitivity to a wide range of therapeutic agents. In the current study, the authors examined whether high-dose tamoxifen (HDT) improved the overall and complete response in patients with metastatic melanoma who were treated with concurrent biochemotherapy. METHODS: Forty-nine patients were treated with a biochemotherapy regimen of dacarbazine, vinblastine, cisplatin, decrescendo interleukin-2, interferon-alpha-2b, and tamoxifen. The study had a 2-step design, beginning with a tamoxifen dose escalation from 40 mg to 320 mg (17 subjects) to evaluate safety and tolerability, followed by Phase II accrual of 32 patients to HDT (320 mg) to assess clinical efficacy. Efficacy was compared with a similar modified biochemotherapy regimen with low-dose tamoxifen (LDT). Pharmacokinetic studies were performed to determine in vivo tamoxifen levels. RESULTS: Tamoxifen dose escalation was completed without any reported dose-limiting toxicity. The overall response rate in the HDT group was 50% (95% confidence interval, 33.2%-66.8%), with a complete response rate of 6% and a median survival of 9.5 months. The overall response rate was not improved and the complete response and survival appeared inferior compared with that of patients recently treated with concurrent biochemotherapy and LDT. Serum tamoxifen levels were found to correlate with the dose administered, with a mean of 0.9 microM at the 40-mg dose to 4.6 microM at the 320-mg dose. Ultrafiltered protein-free sera demonstrated low (< 0.01 microM) concentrations of tamoxifen. CONCLUSIONS: The addition of HDT to a regimen of concurrent biochemotherapy did not appear to improve response rates or overall survival, despite reaching the targeted plasma concentration. Unknown drug interactions or high protein binding of tamoxifen may account for the lack of clinical effectiveness.     

High-dose interleukin-2 in patients with metastatic melanoma whose disease progressed after biochemotherapy

The objective of this study was to report our experience with 38 consecutive patients with metastatic melanoma treated with high-dose (HD) bolus interleukin (IL)-2 after disease progression on or after biochemotherapy as the only earlier treatment for metastatic disease. We conducted a retrospective review of all patients with metastatic melanoma treated with HD IL-2 at the Oncology Center of Hospital Sirio-Libanes between October 2000 and December 2009. The treatment consisted of IL-2, of 600,000 U/kg every 8 h for up to 14 doses, followed by 1-week rest and readmission for the second cycle. Responders received up to four additional cycles. Median follow-up was 9 months. The overall response rate was 23.6%, and we found no correlation between earlier response to biochemotherapy and response to HD IL-2. The median survival was 9.5 months for all patients and 36.1 months for the responders. The most frequent grade 3 or 4 adverse events were hypotension, diarrhea, and respiratory distress, and one patient died from septic shock. We concluded that HD IL-2 has clinically meaningful antitumor activity in patients with metastatic melanoma whose disease has progressed after biochemotherapy. This is a treatment alternative in patients with no central nervous system involvement and who are fit enough to tolerate it, regardless of the initial response to biochemotherapy.     

Serum caspase-1 levels in metastatic melanoma patients: relationship with tumour burden and non-response to biochemotherapy

Interleukin-1beta converting enzymes (ICEs/caspases) are involved in programmed cell death (apoptosis). This study sought to quantify the caspase-1 level in metastatic malignant melanoma patients and to try to establish a correlation between the level of caspase-1 and different parameters related to this pathology. In addition, we evaluated the possible relationship between the clinical response to biochemotherapy and the caspase-1 level. The serum caspase-1 level was determined in 81 metastatic malignant melanoma patients and 50 normal volunteers using enzyme-linked immunosorbent assay (ELISA). Patients received cisplatin, recombinant interleukin-2 (Proleukin) and alpha-interferon (Roferon A) in two induction cycles, and assessment of clinical response was performed according to World Health Organization (WHO) criteria. The median caspase-1 level in melanoma patients was significantly higher (P = 0.0035) than in control samples. Interestingly, a positive correlation between caspase-1 level and the tumour burden was shown (rs = 0.629, P = 0.009). When the clinical response was taken into consideration, the level of caspase-1 was significantly higher in biochemorefractory patients compared with responding ones (P = 0.04). After treatment, the caspase-1 level remained very high in biochemorefractory patients, while in responding ones no change was observed. Furthermore, a positive correlation between the clinical response and the caspase-1 level was established (rs = 0.404, P = 0.024). In conclusion, we observed an elevated caspase-1 level in metastatic malignant melanoma patients. In addition, the correlations obtained between the caspase-1 level and both the tumour burden and the clinical response to the treatment support the concept that disrupted apoptosis pathways might be involved in the progressive disease of advanced melanoma and/or may confer resistance to treatment.     

Long-term survival in metastatic melanoma patients treated with sequential biochemotherapy: report of a Phase II study

The overall survival for patients with metastatic melanoma is very poor, with a median survival of 8.5 months. In this Phase II trial, we assessed the efficacy, safety, and tolerability of a sequential biochemotherapy schedule, using dacarbazine as antiblastic agent and immunomodulant doses of interleukin-2 and interferon-alfa. Thirty-one eligible patients with metastatic melanoma received dacarbazine IV as antiblastic therapy and interluekin-2, plus interferon-alfa SC as sequential immunotherapy, for 6 months. Responding and nonprogressing patients were subsequently maintained on immunotherapy treatment for further 6 months. Twenty-nine patients had an adequate trial, and were assessable for both response and toxicities, with a median follow-up of 49 months. The overall response rate was 52 percent (3 CR and 12 PR), SD was 8 (27 percent) and PD were achieved in 6 patients (21 percent). The median survival duration of responders was 28 months, significantly longer (p < 0.001) than the 16 months of nonresponders. Therapy was well tolerated and produced a significant improvement in progressive-free survival. Further studies, thus, are recommended for larger groups of patients not only to confirm these results, but also to apply this biochemotherapy regimen as adjuvant postsurgical treatment in early stages of malignant melanoma.     

恶性黑色素瘤的生物治疗和生物化疗

OBJECTIVE: To evaluate the efficacy of postoperative biochemotherapy on survival of patients with malignant melanoma. METHODS: One hundred and five patients with malignant melanoma received postoperative biotherapy/biochemotherapy or radiotherapy/chemotherapy. The median time of follow-up was 3 years (from 1 to 5 years). RESULTS: The median survival time (MST) in the whole series of patients was 27 months (range: 2-72 months). The MST in patients received postoperative biotherapy/biochemotherapy (57 cases) was 32 months with a 3-year survival rate of 36.8%. That in patients received postoperative radiotherapy/chemotherapy (54 cases) was 20 months. CONCLUSION: Biotherapy/biochemotherapy following surgery may significantly improve survival in patients with malignant melanoma.     

Lymphocyte function and response to chemo-immunotherapy in patients with metastatic melanoma

Thirty-eight patients with metastatic melanoma were investigated for lymphocyte function immediately prior to chemo-immunotherapy. The pre-treatment immune tests were compared with normal control values and with response to therapy. The "non-responder" group (but not "responder") had significantly reduced values for lymphocyte, null-cell and E-rosette-cell counts compared with controls. Lymphocytoxicity ( using a Chang target cell) showed the same pattern, with depression of direct and K-cell cytotoxic capacity in non-responders compared with controls. Eight patients were studied sequentially whilst on treatment, and demonstrated considerable change (not statistically significant) in lymphocytotoxicity, an untreated "control" patient showed little variation. "Recall"-antigen skin testing showed no statistically significant difference between the patient groups. The data indicate that "non-T-cell activity" may be associated with response to chemo-immunotherapy.     

Long term response to chemotherapy in patients with visceral metastatic melanoma

PATIENTS AND METHODS: Eight patients who remain in long term remission 4 to 15 yearsafter chemotherapy for visceral metastatic melanoma are described.These patients were observed among some 1100 patients with visceralmelanoma seen at the Sydney Melanoma Unit between 1977 and 1989.Only about one-third of such patients received chemotherapy,almost always with single agent dacarbazine or a nitrosourea. RESULTS: The apparently cured patients did not differ from the overallgroup of patients with visceral metastases in baseline characteristics,but 6 of the 8 had nodular lung metastases. CONCLUSIONS: While the mechanism remains uncertain, one possibility couldbe that chemotherapeutic agents cause mutations which allowexpression of antigenicity in tumour cells. In any case, thefact of occasional exceptionally good responses, perhaps amountingto cure, constitutes an argument for a trial of chemotherapyin patients with visceral metastatic melanoma. chemotherapy, melanoma, mutagenesis, prognosis, response     

On the effect of biochemotherapy in metastatic malignant melanoma: an immunopathological evaluation

Although immunotherapy and biochemotherapy have shown promise, producing a subset of durable responses, for the majority of patients with metastatic melanoma the prognosis is still poor. Therefore there is a great need for predictive tests to identify patients with a high probability of responding. Furthermore, there is also a need for a better understanding of the mechanisms of action during treatment in order to be able to monitor the relevant antitumour reactivity during treatment and to optimize the efficacy of future immunotherapy and biochemotherapy. In the present study histopathological regression criteria were used to study the efficacy of biochemotherapy. Thirty-two patients with metastatic malignant melanoma (18 with regional disease and 14 with systemic disease) were treated with biochemotherapy (cisplatin 30 mg/m2 intravenously on days 1-3, dacarbazine 250 mg/m2 intravenously on days 1-3 and interferon-alpha2b 10 million IU subcutaneously 3 days a week, every 28 days). Pre-treatment fine needle aspirates were obtained from metastases to analyse the number of tumour-infiltrating CD4+ lymphocytes. Therapeutic efficacy was evaluated in metastases resected after treatment using histopathological criteria of tumour regression. Comparisons were also made with metastases from 17 untreated patients, all with regional disease. Regressive changes of 25% or more (of the section area) were found in two of the 17 untreated patients with regional disease compared with 13 of the 18 patients with regional disease and 10 of the 14 patients with systemic disease after biochemotherapy. Fifty per cent of the patients with regional disease showed a high degree of regressive changes (75-100% of the section area) after biochemotherapy. These results demonstrate the occurrence of an antitumour reactivity in the majority of patients. Patients with extensive regressive changes in 75-100% of the analysed biopsies were also found to have a longer overall survival (P = 0.019). In patients with regional disease there was a close correlation between a larger number of CD4+ lymphocytes pre-treatment and a higher degree of regressive changes post-treatment (P < 0.05). Thus, immunohistochemical analysis of tumour biopsies shortly after treatment seems to be a good surrogate endpoint. This technique also allows detailed analysis of antitumour reactivity and escape mechanisms.     

Circulating melanoma cells and survival in metastatic melanoma

A validated assay for the enumeration of circulating melanoma cells (CMCs) may facilitate the development of more effective therapies for metastatic melanoma patients. In this study CD146+ cells were immunomagnetically enriched from 7.5 ml of blood. Isolated cells were fluorescently stained with DAPI, anti-molecular weight melanoma-associated antigen (HMW-MAA), anti-CD45 and CD34 and Ki67. CMCs were identified as CD146+, HMW-MAA+, CD45-, CD34-, Ki67-/+ cells. Eighty-eight percent of spiked SK-MEL28 cells in 7.5 ml blood were recovered. In all 55 healthy donors ≤1 CMCs were detected in 7.5 ml of blood. A retrospective analysis was conducted comparing CMC counts and overall survival in 79 blood samples from 44 melanoma patients. CMCs ranged from 0 to 8,042 per 7.5 ml. Two or more CMCs were detected in 18 (23%) of the patients and 30-100% (mean 84%) of the CMCs expressed the proliferation marker Ki67. Patients with ≥2 CMCs per 7.5 ml of whole blood, as compared with the group with <2 CMCs, had a shorter overall survival (2.0 months vs. 12.1 months, P=0.001).     

Antitumor activity of delimotecan against human metastatic melanoma: Pharmacokinetics and molecular determinants

Delimotecan (MEN 4901/T‐0128) is a new cytotoxic prodrug constituted by a camptothecin analog (T‐2513) bound to carboxymethyl dextran through a triglycine linker. A significant antitumor activity of delimotecan against human metastatic melanoma xenograft model Me15392 is reported. Dacarbazine, the drug approved for the treatment of metastatic melanoma, was ineffective in this melanoma model. Pharmacokinetic studies, together with the expression analysis of mRNA for enzymes involved in delimotecan metabolism, showed that T‐2513 and other cytotoxic metabolites of delimotecan (SN 38 and T‐0055) are generated in greater quantities in the tumor tissue than in toxicity target tissues, such as liver, thus accounting for the antitumoral activity. Moreover, we demonstrated that human metastatic melanoma cells are able to phagocytose delimotecan and cleave it to release the cytotoxic moieties T‐2513 in the tumoral environment. Further flow cytometric analysis showed a higher recruitment of macrophages in xenografted human metastatic melanoma, when compared with other human tumors. Thus, the antitumoral activity of delimotecan exerted on metastatic melanoma is due to several factors: (i) the ability of melanoma cells to phagocytose and metabolise delimotecan; (ii) the accumulation of delimotecan in tumoral mass; (iii) the recruitment of macrophage cells to the melanoma nodule and (iv) the expression in melanoma cells of a pattern of enzymes that converts delimotecan into cytotoxic metabolites. Based on these results, delimotecan might be exploited as a new anticancer agent for the therapy of metastatic melanoma because of its high efficacy and good selectivity, and therefore clinical trials for this indication are warranted. © 2009 UICC     

Predictive utility of circulating methylated DNA in serum of melanoma patients receiving biochemotherapy.

PURPOSE: Currently, no validated blood-based assays accurately predict treatment response or outcome in melanoma patients. We hypothesized that methylation of tumor-related genes detected in serum DNA could predict disease outcome and therapeutic response in patients receiving concurrent biochemotherapy (BC) for metastatic melanoma. PATIENTS AND METHODS: American Joint Committee on Cancer stage IV melanoma patients (N = 50) had blood drawn before administration of BC. Patients (n = 47) were classified as BC responders or nonresponders. Responders (n = 23) demonstrated a complete or partial response following BC; nonresponders (n = 24) demonstrated progressive disease. Hypermethylation of Ras association domain family 1 (RASSF1A), retinoic acid receptor-beta2 (RAR-beta2), and O6-methylguanine DNA methyltransferase (MGMT) genes were assessed by methylation-specific polymerase chain reaction. RESULTS: Circulating methylated RASSF1A was significantly less frequent for responders (three of 23 patients; 13%) than nonresponders (10 of 24 patients; 42%; P = .028). Patients with RASSF1A, RAR-beta2, or at least one serum methylated gene had significantly worse overall survival than patients with no methylated genes (log-rank, P = .013, .021, and .01, respectively). Methylated RASSF1A was the only factor that significantly correlated with overall survival and BC response (risk ratio, 2.38; 95% CI, 1.16 to 4.86; P = .018; odds ratio = 0.21; 95% CI, 0.05 to 0.90; P = .036). CONCLUSION: Detection of circulating methylated DNA in serum can predict response to BC and disease outcome.     

Circulating tumor DNA as an early marker of therapeutic response in patients with metastatic colorectal cancer

BackgroundEarly indicators of treatment response in metastatic colorectal cancer (mCRC) could conceivably be used to optimize treatment. We explored early changes in circulating tumor DNA (ctDNA) levels as a marker of therapeutic efficacy.Patients and methodsThis prospective study involved 53 mCRC patients receiving standard first-line chemotherapy. Both ctDNA and CEA were assessed in plasma collected before treatment, 3 days after treatment and before cycle 2. Computed tomography (CT) scans were carried out at baseline and 8–10 weeks and were centrally assessed using RECIST v1.1 criteria. Tumors were sequenced using a panel of 15 genes frequently mutated in mCRC to identify candidate mutations for ctDNA analysis. For each patient, one tumor mutation was selected to assess the presence and the level of ctDNA in plasma samples using a digital genomic assay termed Safe-SeqS.ResultsCandidate mutations for ctDNA analysis were identified in 52 (98.1%) of the tumors. These patient-specific candidate tissue mutations were detectable in the cell-free DNA from the plasma of 48 of these 52 patients (concordance 92.3%). Significant reductions in ctDNA (median 5.7-fold; P < 0.001) levels were observed before cycle 2, which correlated with CT responses at 8–10 weeks (odds ratio = 5.25 with a 10-fold ctDNA reduction; P = 0.016). Major reductions (≥10-fold) versus lesser reductions in ctDNA precycle 2 were associated with a trend for increased progression-free survival (median 14.7 versus 8.1 months; HR = 1.87; P = 0.266).ConclusionsctDNA is detectable in a high proportion of treatment naïve mCRC patients. Early changes in ctDNA during first-line chemotherapy predict the later radiologic response.     

生物化疗、化疗或生物疗法用于治疗恶性黑色素瘤的回顾性分析

背景与目的:近年来恶性黑色素瘤发病率有明显上升趋势,恶性黑色素瘤对单纯放、化疗不甚敏感,然而,它是一种免疫原性较高的肿瘤,联合免疫治疗可以提高疗效,因此,恶性黑色素瘤治疗的合理性在于它的综合治疗.本研究回顾性分析观察Ⅲ、Ⅳ期恶性黑色素瘤患者应用生物化学、生物或化学治疗的近期和远期疗效.方法:分析102例Ⅲ、Ⅳ期恶性黑色素瘤患者化学治疗(达卡巴嗪、顺铂、福莫司汀)、生物治疗(白细胞介素-2、干扰素α-2b、树突状细胞)或生物化疗(上述两者联合续贯)的临床疗效.中位随访时间2年(1至4年).结果:近期疗效:生物化疗组36例,有效率(RR)为69.44%,与生物治疗组(34例,RR29.41%)和化学治疗组(32例,RR 46.89%)相比,差异有显著性(P＜0.05).远期疗效生物化疗组的中位生存时间(MST)为2年9个月,与生物治疗组(MST为2年2个月)和化学治疗组(MST为1年2个月)相比,差异有显著性(P＜0.05).然而,毒副作用在生物化疗明显高于其他两组,但经一般处理,患者均可耐受.结论:恶性黑色素瘤患者经生物化学治疗可明显提高有效率并延长生存时间.     

Factors associated with response to high-dose interleukin-2 in patients with metastatic melanoma.

PURPOSE: The present study attempted to identify characteristics that correlated with clinical response to interleukin (IL)-2 therapy in patients with metastatic melanoma. PATIENTS AND METHODS: We retrospectively evaluated laboratory and clinical characteristics of 374 consecutive patients with metastatic melanoma treated with high-dose intravenous bolus IL-2 (720,000 IU/kg) from July 1, 1988, to December 31, 1999, at the Surgery Branch of the National Cancer Institute. RESULTS: The overall objective response rate was 15.5%. Pretreatment parameters such as patient demographics, laboratory values, and prior therapy did not correlate with response; however, 53.6% of patients with only subcutaneous and/or cutaneous metastases responded, compared with 12.4% of patients with disease at other sites (P2 =.000001). During therapy, patients who were responders tended to have received more doses during course 1 (16.2 +/- 0.3 doses v 14.5 +/- 0.2 doses; P2 =.0095); however, when limited to patients who were able to complete both cycles of course 1, there was no statistically significant difference (P2 =.27). Responders had a higher maximum lymphocyte count immediately after therapy compared with nonresponders (P2 =.0026). The development of abnormal thyroid function tests and vitiligo after therapy was associated with response (thyroid-stimulating hormone, P2 =.01; free T4, P2 =.0049; vitiligo, P2 < 10(-6)), although thyroid dysfunction may have been related more to the length of IL-2 therapy than to response. CONCLUSION: The presence of metastases only to subcutaneous and/or cutaneous sites, lymphocytosis immediately after treatment, and long-term immunologic side effects, especially vitiligo, were associated with antitumor response to IL-2 therapy.