Petr Kavan

Systemic cancer therapy: achievements and challenges that lie ahead

In the last half of the century, advances in the systemic therapy of cancer, including chemotherapy, hormonal therapy, targeted therapy, and immunotherapy have been responsible for improvements in cancer related mortality in developed countries even as the population continues to age. Although such advancements have yet to benefit all cancer types, systemic therapies have led to an improvement in overall survival in both the adjuvant and metastatic setting for many cancers. With the pressure to make therapies available as soon as possible, the side-effects of systemic therapies, in particular long-term side-effects are not very well characterized and understood. Increasingly, a number of cancer types are requiring long-term and even lifelong systemic therapy. This is true for both younger and older patients with cancer and has important implications for each subset. Younger patients have an overall greater expected life-span, and as a result may suffer a greater variety of treatment related complications in the long-term, whereas older patients may develop earlier side-effects as a result of their frailty. Because the incidence of cancer in the world will increase over the next several decades and there will be more people living with cancer, it is important to have an understanding of the potential side-effects of new systemic therapies. As an introductory article, in this review series, we begin by describing some of the major advances made in systemic cancer therapy along with some of their known side-effects and we also make an attempt to describe the future of systemic cancer therapy.

Phase II study of biweekly plitidepsin as second-line therapy in patients with advanced malignant melanoma.

The objective of this study was to evaluate the antitumor activity and safety profile of 5u2009mg/m2 plitidepsin administered as a 3-h continuous intravenous infusion every 2 weeks to patients with advanced malignant melanoma who relapsed or progressed after one line of systemic therapy. Objective response rate (primary efficacy endpoint) was evaluated according to Response Evaluation Criteria In Solid Tumors and toxicity was assessed using National Cancer Institute -Common Toxicity Criteria Version 2.0. Of 39 enrolled patients (median age: 53 years), 37 patients were treated who received a total of 167 treatment cycles (median: 3 cycles per patient; range: 1–32). All patients had received prior systemic therapy with a median of one line per patient (range: 1–6 lines). Of the 35 evaluable patients, two dacarbazine-resistant patients (5.7%) with metastatic cutaneous melanoma achieved partial responses. Five other patients (14.3%) reported stable disease (median stable disease duration: 3.5 months; range: 2.2–15.8 months). Therefore, the rate of tumor growth control was 20.0%. With a median follow-up of 11.0 months, the median progression-free survival was 1.3 months and the median overall survival was 3.5 months. Six patients (16.2%) had the following treatment-related grade 3/4 adverse events: myalgia (nu2009=u20093), injection-site reaction (nu2009=u20092), hypersensitivity, hypotension, and fatigue (nu2009=u20091 each). One patient was withdrawn from the trial because of grade 4 hypersensitivity reaction and hypotension. No severe neutropenia was reported. Plitidepsin showed a minor degree of antitumor activity in patients with refractory advanced malignant melanoma. Further evaluation of plitidepsin in combination schedules may be warranted.

Perioperative chemotherapy with bevacizumab and liver resection for colorectal cancer liver metastasis

BACKGROUNDnSurgery remains the only curative option for patients with colorectal cancer liver metastases (CRLM). Perioperative chemotherapeutic strategies have become increasingly popular in the treatment of CRLM. Although the role of bevacizumab (Bev) in this setting remains unclear, its widespread use has raised concerns about the use of Bev as part of perioperative chemotherapy.nnnMETHODSnWe retrospectively reviewed all patients who received Bev and underwent liver resection between July 2004 and July 2008 at the McGill University Health Center. Chemotherapy-related toxicity, response to chemotherapy, surgical morbidity and mortality, liver function and survival data were assessed.nnnRESULTSnA total of 35 patients were identified. Of these, 26 (74.3%) patients received oxaliplatin-based cytotoxic chemotherapy, six (17.1%) received irinotecan-based therapy and the remainder received both agents. A total of 17 patients (48.6%) underwent portal vein embolization prior to resection and 12 (34.3%) underwent staged resection for extensive bilobar disease. A median of six cycles of preoperative Bev were administered. Nine patients (25.7%) experienced grade 3 or higher chemotherapy-related toxicities. Four events were deemed to be related to Bev. The overall response rate was 65.7% (complete and partial response). One patient progressed on therapy, but this did not prevent R0 resection. The incidence of postoperative morbidity was 42.3%. A total of 21.7% of complications were Clavien grade 3 or higher. There were no perioperative mortalities. There were no cases of severe sinusoidal injury or steatohepatitis. The Kaplan-Meier estimate of 4-year survival was 52.5%.nnnCONCLUSIONSnThese data confirm the safety of chemotherapy regimens which include Bev in the perioperative setting and demonstrate that such perioperative chemotherapy in patients with CRLM does not adversely affect patient outcome. There was no increase in perioperative morbidity compared with published rates. The addition of Bev to standard chemotherapy may improve response rates, which may, in turn, impact favourably on patient survival.

Imiquimod in the Treatment of Breast Cancer Skin Metastasis

Introduction Breast cancer is the most frequently diagnosed cancer in women and the second leading cause of cancer death in women. Of all tumor types, it tends to have a propensity to metastasize to the skin, causing a significant degree of morbidity. A review of the literature reveals a single case report describing the use of topical imiquimod, a synthetic small nucleotide-like compound of the imidazoquinoline family, to successfully treat breast cancer skin metastasis. The exact mechanism of action of imiquimod is not known, but it is an immune response modifier and it has been hypothesized to enhance an immune response against tumors by stimulating dendritic cells and macrophages and by activating inflammatory cytokines and chemokines through toll-like receptors. There is also some evidence that it has antiangiogenic properties and that it can stimulate intrinsic apoptosis. Originally used on genital warts, it has proven beneficial in the treatment of basal cell carcinoma and can be useful in the treatment of skin metastasis from malignant melanoma. We report a case of breast cancer skin metastasis that was successfully treated with imiquimod when radiotherapy and several chemotherapy regimens were unsuccessful and excision was not a viable therapeutic option. In addition to regression of the lesion and an improvement in esthetic appearance, the patient also described a significant reduction in pain from the skin metastasis.

Abstract LB-231: Genomic profiling in serial metastatic colorectal tumors identifies copy number alterations and spatio temporal intra-patient heterogeneity profiles associated with clinical response. Q-CROC-01: NCT00984048

Introduction: Colorectal cancer (CRC) is the third leading cause of cancer related deaths primarily due to its resistance to current treatments. Studies aiming at understanding mechanisms of resistance have largely investigated the genomic landscape of primary tumors at diagnosis. However, selective pressures during therapy can lead to the expansion of resistant clones and tumor heterogeneity. This highlights the need to characterize the molecular changes of metastasis over time of treatment and response to decipher tumor evolution and therapeutic resistance mechanisms. Methods: Metastatic liver tissue samples were collected at baseline (pre-biopsies) and at the time of resistance (post-biopsies) in responder and non-responder CRC patients undergoing the same first-line treatment. Paired pre/post biopsies were collected from 14 patients including 4 patients with multiple post-biopsies to assess temporal and spatio-temporal tumor heterogeneity following treatment exposure. Biopsies were profiled using exome and transcriptome sequencing as well as high-density Single-Nucleotide Polymorphism (SNP) array analysis to capture chromosomal anomalies, loss of heterozygosity and copy number (CN) variations. Results: Profiling of 45 samples with both high-density SNP array and exome sequencing revealed 97.4% similarity between both technologies in the identification of genes targeted by copy number changes. Using chemo-naive biopsies, we identified 120 CN gains and 47 CN loss that were significantly associated with patient progression free survival. Integrative analysis with transcriptome data revealed that only 10% of the genomic CN gains and 17% of the CN loss correlated with their gene expression levels. Based on CN variants comparison between paired pre/post treatment samples, we found high temporal intra-patient heterogeneity over time of treatment. Interestingly, we observed a relationship between heterogeneity and tumor response; showing that acquired resistant tumors have the highest temporal variations. Conclusion: This study, using a multi-omic approach to profile serial liver metastatic samples in CRC patients, highlights the genomic changes in tumor composition after treatment exposure and constitutes an innovative approach to identify clinical biomarkers and molecular signatures of resistance. Citation Format: Mathilde Couetoux du Tertre, Maud Marques, Karen Gambaro, Michael Witcher, Benoit Samson, Bernard Lesperance, Yoo-Joung Ko, Richard Dalfen, Eve St-Hilaire, Lucas Sideris, Felix Couture, Sabine Tejpar, Ronald Burkes, Mohammed Harb, Errol Camlioglu, Adrian Gologan, Vincent Pelsser, Andre Constantin, Suzan McNamara, Petr Kavan, Claudia Kleinman, Gerald Batist. Genomic profiling in serial metastatic colorectal tumors identifies copy number alterations and spatio temporal intra-patient heterogeneity profiles associated with clinical response. Q-CROC-01: NCT00984048 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-231.

Time course of upper limb function and return-to-work post-radiotherapy in young adults with breast cancer: a pilot randomized control trial on effects of targeted exercise program

PurposeBreast cancer (BC) diagnosis in young adults (YA) is rising, and both disease and treatments are aggressive in this population. Evidence supports the use of physical activity in reducing shoulder dysfunction, which is common among BC survivors. A pilot randomized clinical trial was performed to determine the effectiveness of a 12-week post-radiation exercise program in minimizing upper extremity dysfunction in YA with BC.MethodsParticipants were randomized to either an exercise arm or a control arm receiving standard care. Data was collected over six time points using: the Disability of Arm, Shoulder, and Hand (DASH); the Metabolic Equivalent of Task-hours per week (MET-hours/week), and a post hoc questionnaire on return to work.ResultsIn total, 59 young women participated in the study (nxa0=xa029 exercise; nxa0=xa030 control). No statistically significant differences were found in overall DASH results between groups; however, those who underwent total mastectomy had residual upper limb dysfunction (pxa0<xa00.05). Both groups returned to pre-diagnosis activity levels by 18xa0months. Final evaluation showed that 86% of the women returned to work, and 89% resumed prior work activities with a decrease of 8.5xa0h/week.ConclusionAlthough the short-term targeted exercise program had no effect on long-term upper limb function post-radiation, timing and program specificity may require consideration of tissue healing post-radiation and surgery type. The majority of participants returned to work, however not returning to pre-diagnosis work hours.Implications for Cancer SurvivorsExercise interventions alone may not reverse the long-term sequelae of breast cancer treatment and allow young adult patients to return to work.

Abstract 3888: Molecular profiling of sequential biopsies in patients with metastatic colorectal cancer identifies genomic alterations that evolve during first-line therapy and could have therapeutic implications: A prospective study to identify molecular mechanisms of clinical resistance (QCROC-01: NCT00984048).

Therapeutic resistance remains a major obstacle in metastatic colorectal cancer (mCRC) and biomarkers to guide treatment are essential to improving survival and quality of life in mCRC patients. A biopsy-driven prospective study was designed to identify biomarkers and mechanisms of resistance to a standard first-line therapy in patients with mCRC which could be useful in guiding treatment selection (QCROC-01; NCT00984048). We also hoped to recognize molecular changes over time, or resulting from the selection pressure of treatment, which could have implications for subsequent therapy. This study is ongoing and approved at thirteen sites with one-hundred patients enrolled so far. Patients with mCRC receiving FOLFOX (5-fluorouracil, leucovorin and oxaliplatin) with bevacizumab consented to three needle core tumour biopsies at pre-treatment and at the time of resistance. The rate of both patient and physician acceptance of biopsies has steadily risen with time and experience. Serial bloods were also collected for proteomic analysis and circulating tumor DNA. Twenty-five biopsy samples were profiled using exome sequencing (tumor and germ line), RNAseq, low pass genome sequencing and miRNA analysis. Differential gene expression analysis revealed signatures associated with clinical response and resistance when comparing tumours obtained pre- and post-treatment. We detect changes in variant allele fraction including both depletion and enrichment of individual somatic mutations over the course of treatment, the latter of which may indicate subclonal and acquired “driver” mutations that confer therapeutic resistance. A small number of genes show recurrent evidence for changes in clonal enrichment at the time of relapse across multiple patients. These could also represent therapeutic targets for subsequent therapy for these patients, and as such, represent new treatment opportunities. Our findings provide insights into tumor evolution during first-line chemotherapy of mCRC that may hold clues to optimize current first-line therapeutic decision making and identifies potential target pathways for second-line stratification of patients. This study is part of the Canadian Colorectal Cancer Consortium which is a multi-site collaboration funded by the Terry Fox Research Institute and le fonds de recherche du quebec - sante. Citation Format: Suzan McNamara, Ryan Morin, Mathilde Couetoux du Tertre, Rosemary McCloskey, Rebecca Johnston, Daniel Fornika, Benoit Samson, Bernard Lesperance, Thierry Alcindor, Yoo-Joung Ko, Richard Dalfen, Eve St-Hilaire, Lucas Sideris, Felix Couture, Hans Prenen, Sabine Tejpar, Ronald Burkes, Andre Constantin, Errol Camlioglu, Adriana Aguilar, Adrian Gologan, Benoit Tetu, Celia M. Greenwood, Cyrla Hoffert, Samia Qureshi, Zuanel Diaz, Maud Marques, Micheal Witcher, Therese Gagnon-Kugler, Petr Kavan, Gerald Batist. Molecular profiling of sequential biopsies in patients with metastatic colorectal cancer identifies genomic alterations that evolve during first-line therapy and could have therapeutic implications: A prospective study to identify molecular mechanisms of clinical resistance (QCROC-01: NCT00984048). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3888. doi:10.1158/1538-7445.AM2015-3888