Vincent C. Tam

Compendium of Unpublished Phase III Trials in Oncology: Characteristics and Impact on Clinical Practice

PURPOSE Many phase III trials presented at annual meetings of the American Society of Clinical Oncology (ASCO) remain unpublished. The results of these unpublished trials, if more generally known, might have an impact on clinical practice. METHODS Abstracts of large phase III trials evaluating systemic cancer treatment were identified from conference proceedings of the 1989 to 2003 ASCO annual meetings. PubMed, Medline, and Embase were searched for corresponding publications. A compendium of unpublished phase III trials was assembled. Clinical significance of nonpublication was determined by disease site-specific oncology experts from two academic cancer centers in Canada. RESULTS A total of 709 phase III trials were identified of which 66 (9.3%) remain without a subsequent publication at a minimum of 6.5 years of follow-up and 94 (13%) were published after a delay of ≥ 5 years from their initial presentation. Of the unpublished trials, 48% were presented as oral sessions at an ASCO meeting, and 71% of the abstracts reported negative results. The experts judged that 70% of the unpublished trials addressed an important question and 59% might have had clinical impact if their results had been published promptly. CONCLUSION A substantial number of cancer clinical trials with potential influence on clinical practice remain unpublished and many other trials are published after a substantial delay. Nonpublication of clinical trials breaks an implicit contract with participants, institutional review boards, and sponsors.

Consistency of Phase III Clinical Trial Abstracts Presented at an Annual Meeting of the American Society of Clinical Oncology Compared With Their Subsequent Full-Text Publications

PURPOSE This study aimed to determine the consistency of phase III clinical trial abstracts presented at American Society of Clinical Oncology (ASCO) Annual Meetings compared with their subsequent full-text publications. METHODS We identified abstracts describing phase III clinical trials of chemotherapy, chemoradiotherapy, immunotherapy, and hormone therapy presented at the 36th ASCO Annual Meeting in May 2000. We searched MEDLINE and PubMed for all corresponding publications. Data were extracted from the abstracts and publications that met our inclusion criteria. RESULTS A total of 192 abstracts were identified. Seventy-four abstracts met our inclusion criteria. Six years after the 2000 ASCO Meeting, 74% of abstracts had corresponding publications. The primary end point was stated in 34% of abstracts and 100% of published papers. The primary end point result differed by more than 5% between the abstract and publication in 42% of comparisons. The statistical significance of the primary end point and study conclusions were consistent between abstracts and subsequent publications in 89% and 91% of the comparisons, respectively. Abstracts selected as plenary or oral presentations were significantly more likely to be published. No factors predicted consistency for primary end point significance and overall conclusion between ASCO abstracts and their journal publications. CONCLUSION When carefully selected, ASCO Annual Meeting abstracts of phase III trials consistently reflect final published results, but some differences were observed that warrant caution in using abstract results to shape treatment decisions before full publication.

Oncology education in Canadian undergraduate and postgraduate medical programs: a survey of educators and learners

BACKGROUND The oncology education framework currently in use in Canadian medical training programs is unknown, and the needs of learners have not been fully assessed to determine whether they are adequately prepared to manage patients with cancer. METHODS To assess the oncology education framework currently in use at Canadian medical schools and residency training programs for family (fm) and internal medicine (im), and to evaluate opinions about the content and utility of standard oncology education objectives, a Web survey was designed and sent to educators and learners. The survey recipients included undergraduate medical education curriculum committee members (umeccms), directors of fm and im programs, oncologists, medical students, and fm and im residents. RESULTS Survey responses were received from 677 educators and learners. Oncology education was felt to be inadequate in their respective programs by 58% of umeccms, 57% of fm program directors, and 50% of im program directors. For learners, oncology education was thought to be inadequate by 67% of medical students, 86% of fm residents, and 63% of im residents. When comparing teaching of medical subspecialty-related diseases, all groups agreed that their trainees were least prepared to manage patients with cancer. A standard set of oncology objectives was thought to be possibly or definitely useful for undergraduate learners by 59% of respondents overall and by 61% of postgraduate learners. CONCLUSIONS Oncology education in Canadian undergraduate and postgraduate fm and im training programs are currently thought to be inadequate by a majority of educators and learners. Developing a standard set of oncology objectives might address the needs of learners.

Tumour thrombus of the inferior vena cava extending into the right atrium in the setting of colon cancer

Tumour thrombus is seen in renal cell and hepatocellular carcinoma, but is rarely reported in colorectal cancer. A woman aged 46 years, with metastatic colonic adenocarcinoma, was found to have a large mass in the inferior vena cava (IVC) extending into the right atrium. Although this lesion was initially thought to be bland thrombus, imaging with contrast-enhanced CT scan and contrast-enhanced ultrasound supported the diagnosis of tumour thrombus. Despite the large size of the lesion, the patient was asymptomatic. Her lack of symptoms, and poor overall prognosis from her cancer led to the decision to avoid aggressive surgical or radiological interventions. Several months later, the patient passed away. At autopsy, there was no evidence of fatal embolisation from the pre-existing thrombus. Diagnosis of tumour thrombus in the IVC is difficult and management can be challenging due to the significant risks associated with treatment options.

Oncology education for Canadian internal medicine residents: the value of participating in a medical oncology elective rotation

Background Despite the high incidence and burden of cancer in Canadians, medical oncology (mo) rotations are not mandatory in most Canadian internal medicine (im) residency training programs. Methods All im residents scheduled for a mo rotation at 4 Canadian teaching cancer centres between 1 January 2013 and 31 December 2015 were invited to complete an online survey before and after their rotation. The survey was designed to evaluate perceptions of oncology, comfort in managing cancer patients, and basic oncology knowledge. Results The survey was completed by 68 im residents pre-rotation and by 48 (71%) post-rotation. Cancer-related learning was acquired mostly from mo physicians in clinic (35%). Self-directed learning, didactic teaching, and resident or fellow teaching accounted for 31%, 26%, and 10% respectively of learning acquisition. Comfort level in dealing with cancer patients and patients at end of life improved to 4.0/5 from 3.2/5 (p < 0.001) and to 4.0/5 from 3.6/5 (p = 0.003) respectively. Mean knowledge assessment score improved to 83% post-rotation from 76% pre-rotation (p = 0.003), with the greatest increase observed in general knowledge of common malignancies. The 3 topics ranked as most important to learn during a mo rotation were oncologic emergencies, common complications of treatment, and approach to diagnosis of cancer. Conclusions A rotation in mo improves the perceptions of im residents about oncology and their comfort level in dealing with cancer patients and patients at end of life. Overall cancer knowledge is also improved. Given those benefits, im residency programs should encourage most of their residents to complete a mo rotation.

Prognosis of patients with hepatocellular carcinoma treated with sorafenib: a comparison of five models in a large Canadian database

Several systems (tumor‐node‐metastasis [TNM], Barcelona Clinic Liver Cancer [BCLC], Okuda, Cancer of the Liver Italian Program [CLIP], and albumin–bilirubin grade [ALBI]) were developed to estimate the prognosis of patients with hepatocellular carcinoma (HCC) mostly prior to the prevalent use of sorafenib. We aimed to compare the prognostic and discriminatory power of these models in predicting survival for HCC patients treated with sorafenib and to identify independent prognostic factors for survival in this population. Patients who received sorafenib for the treatment of HCC between 1 January 2008 and 30 June 2015 in the provinces of British Columbia and Alberta, and two large cancer centers in Toronto, Ontario, were included. Survival was assessed using the Kaplan–Meier method. Multivariate Cox regression was used to identify predictors of survival. The models were compared with respect to homogeneity, discriminatory ability, monotonicity of gradients, time‐dependent area under the curve, and Akaike information criterion. A total of 681 patients were included. 80% were males, 86% had Child–Pugh class A, and 37% of patients were East Asians. The most common etiology for liver disease was hepatitis B (34%) and C (31%). In all model comparisons, CLIP performed better while BCLC and TNM7 performed less favorably but the differences were small. The utility of each system in allocating patients into different prognostic groups varied, for example, TNM poorly differentiated patients in advanced stages (8.7 months (m) (95% CI 6.5–11.5) versus 8.4 m (95% CI 7.0–9.6) for stages III and IV, respectively) while ALBI had excellent discrimination of early grades (15.6 m [95% CI 13.0–18.4] versus 8.3 m [95% CI 7.0–9.2] for grades 1 and 2, respectively). On multivariate analysis, hepatitis C, alcoholism, and prior hepatic resection were independently prognostic of better survival (P < 0.01). In conclusion, none of the prognostic systems was optimal in predicting survival in sorafenib‐treated patients with HCC. Etiology of liver disease should be considered in future models and clinical trial designs.

The Evolution of Metastatic Colorectal Cancer Clinical Trials: Application of the ASCO Framework for Assessing Value

Background: Phase III trials in metastatic colorectal cancer (mCRC) have collectively led to progressive advancements in patient outcomes over the past decades. This study characterizes the evolution of mCRC phase III trials through assessing the value of cancer therapy, as measured by the ASCO Value Framework. Methods: Phase III trial results of systemic therapy for mCRC published between 1980 and 2015 were identified, and their outcome, statistical significance, journal impact factor, and citation by the 2016 NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for CRC were recorded. For each trial, the net health benefit (NHB) score was calculated using the June 2015 (original) and May 2016 (revised) ASCO Value Framework: Advanced Disease. Results: There were 114 mCRC phase III trials eligible for calculation of the NHB score. Using the revised framework, the median NHB score was 4.6 (range, -30 to 43.5); 12% of trials received bonus points. Trials with statistically significant results had higher NHB scores compared with nonsignificant trials (median NHB score, 21.6 vs 2.9; P<.0001). Clinical trials cited in the NCCN Guidelines had higher NHB scores than those not cited (median score, 8.0 vs 0.3; P=.02). In multivariate linear regression analysis, the only significant predictor of high NHB score was statistically significant studies. Conclusions: The median NHB score for mCRC phase III trials was 4.6. Higher NHB scores are associated with statistically significant studies and are cited in the NCCN Guidelines, a surrogate for practice-changing trials. The 2016 ASCO Value Framework may not fully capture the benefits on an individual patient level.