Updating Reports of Phase 3 Clinical Trials for Cancer.

IMPORTANCE: Phase 3 randomized clinical trials (RCTs) are usually reported after a predetermined number of events (death or disease progression) have occurred, when survival curves remain poorly defined. Updated reports are important in providing mature data. OBJECTIVES: To evaluate the proportion of phase 3 RCTs for cancer that are updated and the factors that are associated with updating them and, for updated trials, to compare initial and updated results. DESIGN, SETTING, AND PARTICIPANTS: This study identified reports of 2-group RCTs with a sample size of at least 100, published in 6 major journals between 1990 and 2010, that evaluated drug treatments for breast, lung, or prostate cancer. PubMed and abstracts of large cancer conferences were searched to identify updated (or earlier) reports of the same trials published up to 2019. Logistic regression was used to identify factors associated with the provision of updated reports. The hazard ratios defining the relative treatment effects for the primary and secondary end points between the initial and updated reports were compared. MAIN OUTCOMES AND MEASURES: Proportion of RCTs whose results are updated, factors associated with updating, and change in hazard ratio for the primary end point between initial and updated reports. RESULTS: A total of 207 RCTs met the inclusion criteria, and 41 (20%) were found to have updated reports. The factors significantly associated with an update included positive trial results (odds ratio [OR], 8.7 [95% CI, 3.3-23.3]), larger trial size (OR, 1.0006 [95% CI, 1.0000-1.0012]), evaluation of hormonal agents (OR, 5.8 [95% CI, 1.6-21.8]) or targeted agents (OR, 4.3 [95% CI, 1.3-14.6]) compared with chemotherapy, and evaluation of adjuvant therapy rather than therapy for advanced disease (OR, 8.0 [95% CI, 2.9-21.9]). For 31 trials for which initial and updated hazard ratios for the primary end point were available, the median hazard ratio increased from 0.66 (95% CI, 0.22-1.20) to 0.74 (95% CI, 0.32-1.19) (P < .001), indicating a decreased level of effectiveness. CONCLUSIONS AND RELEVANCE: Only 20% of reports of phase 3 clinical trials for breast, lung, and prostate cancer were updated. Original reports of such trials are based on relatively few events, and their results are immature; more mature data indicate a decreased level of effect in updated trials. Updated reporting to provide mature, long-term results of clinical trials should be mandated.

Chemoradiotherapy Using Carboplatin plus Paclitaxel versus Cisplatin plus Fluorouracil for Esophageal or Gastroesophageal Junction Cancer.

BACKGROUND: Trimodality therapy (TMT) with neoadjuvant chemoradiotherapy (nCRT) using concurrent carboplatin plus paclitaxel (CP) followed by surgery is the standard of care for locoregional esophageal or gastroesophageal junction (GEJ) cancers. Alternatively, nCRT with cisplatin plus fluorouracil (CF) can be used. Definitive chemoradiotherapy (dCRT) with CP or CF can be used if surgery is not planned. In the absence of comparative trials, we aimed to evaluate outcomes of CP and CF in the settings of TMT and dCRT. METHODS: A single-site, retrospective cohort study was conducted at the Princess Margaret Cancer Centre to identify all patients who received CRT for locoregional esophageal or GEJ cancer. Overall survival (OS) and disease-free survival (DFS) were assessed using the Kaplan-Meier method and multivariable Cox regression model. The inverse probability treatment weighting (IPTW) method was used for sensitivity analysis. RESULTS: Between 2011 and 2015, 93 patients with esophageal (49%) and GEJ (51%) cancers underwent nCRT (n = 67; 72%) or dCRT (n = 26; 28%). Median age was 62.3 years and 74% were male. Median follow-up was 23.9 months. Comparing CP to CF in the setting of TMT, the OS and DFS rates were similar. In the setting of dCRT, CP was associated with significantly inferior 3-year OS (36 vs. 63%; p = 0.001; HR 3.1; 95% CI: 1.2-7.7) and DFS (0 vs. 41%; p = 0.004; HR 3.6; 95% CI: 1.4-8.9) on multivariable and IPTW sensitivity analyses. CONCLUSIONS: TMT with CF and CP produced comparable outcomes. However, for dCRT, CF may be a superior regimen.

Surveillance and outcomes after curative resection for gastroesophageal adenocarcinoma.

BACKGROUND: The goal of surveillance testing is to enable curative salvage therapy through early disease detection, however supporting evidence in gastroesophageal adenocarcinoma is limited. We evaluated frequency of successful salvage therapy and outcomes in patients who underwent surveillance. METHODS: A single-site, retrospective cohort study was conducted to identify all patients who received curative resection for gastroesophageal adenocarcinoma. Surveillance testing were those investigations not triggered by abnormal symptoms, physical examination, or blood tests. Successful salvage therapy was any potentially curative therapy for disease recurrence which resulted in postrecurrence disease-free survival ≥2 years. Time-to-event data were analyzed using the Kaplan-Meier method and log rank tests. RESULTS: Between 2011 and 2016, 210 consecutive patients were reviewed. Esophageal (14%), gastroesophageal junction (40%), and gastric adenocarcinomas (45%) were treated with surgery alone (29%) or multimodality therapy (71%). Adjuvant therapy was administered in 35%. At median follow-up of 38.3 months, 5-year overall survival (OS) rate was 56%. Among 97 recurrences, 53% were surveillance-detected, and 46% were symptomatic. None was detected by surveillance endoscopy. Median time-to-recurrence (TTR) was 14.8 months. Recurrences included locoregional only (4%), distant (86%), and both (10%). Salvage therapy was attempted in 15 patients, 4 were successful. Compared to symptomatic recurrences, patients with surveillance-detected recurrences had longer median OS (36.2 vs 23.7 months, P = .004) and postrecurrence survival (PRS, 16.5 vs 4.6 months, P < .001), but similar TTR (16.2 vs 13.3 months, P = .40) and duration of palliative chemotherapy (3.9 vs 3.3 months, P = .64). CONCLUSIONS: Among patients surveyed, 96% of recurrences were distant, and salvage therapy was successful in only 1.9% of patients. Longer OS in patients with surveillance-detected compared to symptomatic recurrences was not associated with significant earlier disease detection, and may be contributed by differences in disease biology. Further prospective data are warranted to establish the benefit of surveillance testing in gastroesophageal adenocarcinoma.

Long term responders to palliative chemotherapy for advanced biliary tract cancer.

BACKGROUND: Patients with advanced biliary tract cancer (BTC) are often treated with palliative chemotherapy (PC). Standard PC since 2010 is a cisplatin/gemcitabine doublet, with median overall survival (OS) of 11.7 months from the ABC-02 trial. Prior to this, our institutional standard was gemcitabine and fluoropyrimidine. The ABC-02 study used 8 cycles of PC as standard with treatment stopped even in the absence of disease progression, but some patients may benefit from continuing PC longer than 8 cycles. METHODS: Patients treated with at least 2 cycles of PC for advanced BTC in Princess Margaret Cancer Centre between 1987 and 2015 were included, and divided into 2 groups for analysis-long-term responders (LTR) who received 9 or more cycles, and controls (2-8 cycles). Data was collected on demographics, clinicopathological features, PC regimen, toxicities, and survival. The primary outcome measure was OS, with secondary analyses including progression-free survival (PFS) and toxicity rates between groups. RESULTS: A total of 382 patients were identified, 123 who met the criteria for LTR and 259 who were included as controls. The baseline demographic and clinical characteristics were similar, although more patients in the control group had gallbladder cancer or extrahepatic cholangiocarcinoma than LTR (P=0.024), and more patients in the LTR group were treated with combination chemotherapy regimens (93% vs. 82% in controls, P=0.003). The LTR patients had significantly longer PFS (median 13.3 vs. 4.1 months, P<0.001) and longer OS than controls (median 22.1 vs. 9.2 months, P<0.001). In LTR patients, 15% had a break from chemotherapy of 3 months or more and restarted the same regimen. The LTR patients reported higher rates of nausea, cutaneous and hematologic toxicity, but also more frequently went on to receive second-line chemotherapy (47% vs. 33%, P=0.007). In multivariable analysis of OS, LTR, good performance status and intrahepatic site of cancer were associated with better survival. CONCLUSIONS: From this institutional dataset, a significant proportion of patients continued chemotherapy past 8 cycles, and appeared to derive benefit from longer duration of treatment. Toxicity rates were higher in this group, but manageable as evidenced by second-line treatment rates. Discontinuation of chemotherapy for reasons other than toxicity or progression may result in loss of disease control and impact survival in this population; these data suggest the use of continued chemotherapy to disease progression in patients with advanced BTC is a favorable option.