Joleen M. Hubbard

Association Between Disease-Free Survival and Overall Survival When Survival Is Prolonged After Recurrence in Patients Receiving Cytotoxic Adjuvant Therapy for Colon Cancer: Simulations Based on the 20,800 Patient ACCENT Data Set

PURPOSE We previously validated disease-free survival (DFS) as a surrogate for overall survival (OS) in fluorouracil-based adjuvant colon cancer clinical trials. New therapies have extended survival after recurrence from 1 to approximately 2 years. We examined the possible impact of this improvement on the DFS/OS association. METHODS The Adjuvant Colon Cancer Endpoints (ACCENT) data set of 20,898 patients was analyzed. In an exploratory fashion, time from recurrence to death in patients experiencing recurrence was extended using several algorithms, and the association of DFS after 3 years of median follow-up and OS after varying lengths of follow-up (median of 5, 6, and 7 years) was assessed. RESULTS Seven thousand four hundred two patients (35%) experienced recurrence. Median time from recurrence to death was 24 months in the hypothetical data sets. When times from recurrence to death were doubled, the association between treatment effects on DFS and 5-year OS was modest (R(2) = 0.51 for both 2- and 3-year DFS) but remained strong for DFS and 6-year OS (R(2) = 0.67 for both 2- and 3-year DFS) and 7-year OS (R(2) = 0.70 for both 2- and 3-year DFS). The reduced DFS/OS association with extended survival after recurrence was greater in stage II than stage III patients. Multiple simulations provided consistent findings. CONCLUSION Extended survival after recurrence reduces the association between treatment effects on 3-year DFS and 5-year OS, particularly in stage II patients; longer follow-up strengthens the association. In modern adjuvant trials, 6 or 7 years may be required to demonstrate OS improvements, further supporting DFS as the preferred primary end point for future adjuvant colon cancer clinical trials.

Patient and Tumor Characteristics and BRAF and KRAS Mutations in Colon Cancer, NCCTG/Alliance N0147

BACKGROUND KRAS and BRAF (V600E) mutations are important predictive and prognostic markers, respectively, in colon cancer, but little is known about patient and clinical factors associated with them. METHODS Two thousand three hundred twenty-six of 3397 patients in the N0147 phase III adjuvant trial for stage III colon cancer completed a patient questionnaire. Primary tumors were assessed for KRAS and BRAF (V600E) mutations and defective mismatch repair (dMMR) status. Logistic regression models and categorical data analysis were used to identify associations of patient and tumor characteristics with mutation status. All statistical tests were two-sided. RESULTS KRAS (35%) and BRAF (V600E) (14%) mutations were nearly mutually exclusive. KRAS mutations were more likely to be present in patients without a family history of colon cancer and never smokers. Tumors with KRAS mutations were less likely to have dMMR (odds ratio [OR] = 0.21; 95% confidence interval [CI] = 0.15 to 0.31; P < .001) and high-grade histology (OR = 0.73; 95% CI = 0.59 to 0.92; P < .001) but were more often right-sided. Among KRAS-mutated tumors, those with a Gly13Asp mutation tended to have dMMR and high-grade histology. Tumors with BRAF (V600E) mutations were more likely to be seen in patients who were aged 70 years or older (OR = 3.33; 95% CI = 2.50 to 4.42; P < .001) and current or former smokers (OR = 1.64; 95% CI = 1.26 to 2.14; P < .001) but less likely in non-whites and men. Tumors with BRAF (V600E) mutations were more likely to be right-sided and to have four or more positive lymph nodes, high-grade histology, and dMMR. CONCLUSIONS Specific patient and tumor characteristics are associated with KRAS and BRAF (V600E) mutations.

Incorporating Biomarkers Into Cancer and Aging Research

The challenge in treating the older adult with cancer is accurately accounting for and adapting management to the heterogeneity in health status of the individual patient. Many oncologists recognize that chronological age alone should not be the determinant when deciding on a treatment regimen. Easily measurable markers that provide an assessment of functional age would be ideal to assess frailty, which may predispose the patient to complications from cancer treatment, including increased toxicity, functional decline, decreased quality of life, and poorer survival. Several categories of potential markers, including chronic inflammatory markers, markers of cellular senescence, and imaging to assess muscle mass to detect sarcopenia, may provide insight into the likelihood of treatment-related complications. This article discusses candidate markers and strategies to evaluate these markers in cancer treatment trials, with the aim of developing a method to assess risk of oncologic outcomes and guide management decisions for both the physician and patient.

Antiangiogenesis Agents in Colorectal Cancer

Purpose of review The vascular endothelial growth factor (VEGF) system is a critical regulator of angiogenesis and known to promote tumor growth and invasion in colorectal cancer (CRC). Bevacizumab is currently the only VEGF inhibitor with clear proof of efficacy in CRC, but optimal use of this agent at various stages of the disease is still under investigation. Additionally, there are numerous other angiogenesis agents targeting VEGF and other proangiogenic systems in clinical development. Recent findings Although bevacizumab has been shown to improve outcomes in terms of progression-free and overall survival in the setting of metastatic CRC (mCRC), it does not appear to provide long-term benefit in the adjuvant setting. The combination of VEGF inhibition with epidermal growth factor inhibition with chemotherapy does not improve survival for patients with mCRC, and may potentially be harmful in the first-line setting. Tyrosine kinase inhibitors in combination with other therapies show promise in early clinical trials in mCRC. Summary Current evidence suggests that the benefit of VEGF inhibition with bevacizumab in CRC is limited to the metastatic setting. Dual antibody therapy with bevacizumab and an epidermal growth factor inhibitor (cetuximab or panitumumab) should not be used in mCRC. Results of ongoing trials involving tyrosine kinase inhibitors may result in an expansion of treatment options for patients with CRC.

Non-V600BRAF Mutations Define a Clinically Distinct Molecular Subtype of Metastatic Colorectal Cancer

Purpose Molecular diagnostic testing has become an integral part of the evaluation of patients with metastatic colorectal cancer (CRC). Expanded mutational testing, such as next-generation sequencing (NGS), often identifies mutations with unclear clinical or prognostic implications. One such example is BRAF mutations that occur outside of codon 600 (non-V600 BRAF mutations). Methods We conducted this multicenter, retrospective cohort study to characterize the clinical, pathologic, and survival implications of non-V600 BRAF mutations in metastatic CRC. We pooled patients in whom non-V600 BRAF mutations were identified from NGS databases at three large molecular genetics reference laboratories. Results A total of 9,643 patients with metastatic CRC underwent NGS testing. We identified 208 patients with non-V600 BRAF mutations, which occurred in 2.2% of all patients tested and accounted for 22% of all BRAF mutations identified. Cancers with non-V600 BRAF mutations, compared with cancers with V600E BRAF (V600E BRAF) mutations, were found in patients who were significantly younger (58 v 68 years, respectively), fewer female patients (46% v 65%, respectively), and patients who had fewer high-grade tumors (13% v 64%, respectively) or right-sided primary tumors (36% v 81%, respectively). Median overall survival was significantly longer in patients with non-V600 BRAF-mutant metastatic CRC compared with those with both V600E BRAF-mutant and wild-type BRAF metastatic CRC (60.7 v 11.4 v 43.0 months, respectively; P < .001). In multivariable analysis, non-V600 BRAF mutation was independently associated with improved overall survival (hazard ratio, 0.18; P < .001). Conclusion Non-V600 BRAF mutations occur in approximately 2.2% of patients with metastatic CRC and define a clinically distinct subtype of CRC with an excellent prognosis.

Colorectal cancer in 2014: Progress in defining first-line and maintenance therapies

The results of several clinical trials in metastatic colorectal cancer presented in 2014 will influence clinical practice. These findings include definitive data from phase III trials comparing bevacizumab and cetuximab-based therapy in the first-line, studies elucidating the value of maintenance therapy after induction treatment, and data on new agents in this disease.

Benefits and Adverse Events in Younger Versus Older Patients Receiving Adjuvant Chemotherapy for Colon Cancer: Findings From the Adjuvant Colon Cancer Endpoints Data Set

PURPOSE Limited data exist regarding the outcomes of adjuvant therapy in younger patients with stage II and III colon cancer. We examined disease-free survival (DFS), overall survival (OS), recurrence-free interval (RFI), and grade 3+ adverse events (AEs) in younger patients in the 33,574 patient Adjuvant Colon Cancer Endpoints Group data set. PATIENTS AND METHODS Individual patient data from 24 randomized phase III clinical trials were obtained for survival outcomes, which included 10 clinical trials for AE outcomes. Two age-based cutoff points were used to define younger patients: age younger than 40 years and younger than 50 years. Adjuvant therapy benefit analyses were limited to the nine clinical trials in which the investigational chemotherapeutic arm demonstrated benefit. RESULTS One thousand seven hundred fifty-eight patients (5.2%) were younger than 40 years, 5,817 patients (17.3%) were younger than 50 years, and only 299 patients (0.9%) were younger than 30 years. No meaningful differences in sex or stage were noted in younger versus older patients. Younger and older patients did not differ in RFI (age, < 40 years: hazard ratio [HR], 1.0; P = .62 and age < 50 years: HR, 1.02; P = .35). Younger patients (both cutoff points), had longer OS and DFS than older patients. In trials demonstrating adjuvant therapy benefit, similar DFS benefit was observed by age. Younger patients experienced less leukopenia and stomatitis, but more frequent nausea/vomiting. CONCLUSION Among patients on clinical trials, younger and older patients with stage II and III colon cancer had similar RFI and adjuvant therapy benefit. Younger patients have longer OS and DFS, which is likely primarily because of fewer competing causes of death. Adjuvant therapy is beneficial for colon cancer in patients younger than 50 years who meet typical clinical trial eligibility criteria.

Napabucasin: An Update on the First-in-Class Cancer Stemness Inhibitor

Napabucasin (BBI608) is an orally administered small molecule that blocks stem cell activity in cancer cells by targeting the signal transducer and activator of transcription 3 pathway. The signal transducer and activator of transcription 3 pathway is over-activated in many types of cancer and has been shown to be an important pathway in cancer stem cell-mediated propagation of cancer. Cancer stem cells are a subpopulation of cancer cells considered to be the primary source of tumor growth, metastasis, and resistance to conventional therapies, and thus, responsible for cancer relapse. This review describes the clinical development program of this first-in-class cancer stemness inhibitor, including preclinical discovery, early clinical trials, current phase III clinical trial evaluation, and future therapeutic combinations. The therapeutic potential of napabucasin was first reported in a preclinical study that demonstrated the potent anti-tumor and anti-metastatic activity of napabucasin in several different cancer types, both in vitro and in vivo. In mouse models, napabucasin was effective both as a monotherapy and in combination with other agents; in particular, synergy was observed with paclitaxel in vivo. Napabucasin clinical trials have demonstrated encouraging anti-tumor activity as monotherapy and in combination with conventional therapeutics, with no significant pharmacokinetic interactions when used in combination therapies. Adverse events attributed to napabucasin have been predominantly mild, although some patients have experienced grade 3 gastrointestinal adverse events. More severe adverse events required reduced or discontinued dosing of napabucasin or medication to reverse or manage symptoms. In conclusion, napabucasin may prove useful in targeting cancer stem cells, with the potential to suppress metastasis and prevent relapse in patients with varying cancer types.

Older adult oncology, version 2.2016: Featured updates to the NCCN guidelines

Cancer is the leading cause of death in older adults aged 60 to 79 years. Older patients with good performance status are able to tolerate commonly used treatment modalities as well as younger patients, particularly when adequate supportive care is provided. For older patients who are able to tolerate curative treatment, options include surgery, radiation therapy (RT), chemotherapy, and targeted therapies. RT can be highly effective and well tolerated in carefully selected patients, and advanced age alone should not preclude the use of RT in older patients with cancer. Judicious application of advanced RT techniques that facilitate normal tissue sparing and reduce RT doses to organs at risk are important for all patients, and may help to assuage concerns about the risks of RT in older adults. These NCCN Guidelines Insights focus on the recent updates to the 2016 NCCN Guidelines for Older Adult Oncology specific to the use of RT in the management of older adults with cancer.

Physician Perspective on Incorporation of Oncology Patient Quality-of-Life, Fatigue, and Pain Assessment Into Clinical Practice

PURPOSE Patient-reported outcomes (PROs) such as pain, fatigue, and quality of life (QOL) are important for morbidity and mortality in patients with cancer. Systematic approaches to collect and incorporate PROs into clinical practice are still evolving. We set out to determine the impact of PRO assessment on routine clinical practice. METHODS Beginning in July 2010, the symptom assessment questionnaire (SAQ) was administered to every patient in a solid tumor oncology practice at an academic center. The SAQ measures pain, fatigue, and QOL, each on a scale of 0 to 10 points. Results were available to providers before each visit in the electronic medical record. Eighteen months after the SAQ was implemented, an online survey was sent to 83 oncology care providers regarding the use of the SAQ and how it affected their clinical practice, including discussion with patients, duration of visits, and work burden. RESULTS A total of 53% of care providers completed the online survey, producing 44 evaluable surveys. Of these, 86% of care providers reported using information from the SAQ; > 90% of care providers indicated the SAQ did not change the length of clinic visits or contribute to increased work burden. A majority of care providers felt that the SAQ had helped or enhanced their practice. Providers endorsed the SAQ for facilitating communication with their patients. CONCLUSION This study indicates that simple single-item measures of pain, fatigue, and QOL can be incorporated into oncology clinical practice with positive implications for both patients and physicians without increasing duration of visits or work burden.