In lifetesting, medical follow-up, and other fields the observation of the time of occurrence of the event of interest (called a death) may be prevented for some of the items of the sample by the previous occurrence of some other event (called a loss). Losses may be either accidental or controlled, the latter resulting from a decision to terminate certain observations. In either case it is usually assumed in this paper that the lifetime (age at death) is independent of the potential loss time; in practice this assumption deserves careful scrutiny. Despite the resulting incompleteness of the data, it is desired to estimate the proportion P(t) of items in the population whose lifetimes would exceed t (in the absence of such losses), without making any assumption about the form of the function P(t). The observation for each item of a suitable initial event, marking the beginning of its lifetime, is presupposed. For random samples of size N the product-limit (PL) estimate can be defined as follows: L...

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Nonparametric Estimation from Incomplete Observations

Background Preclinical and preliminary clinical data indicate that ch14.18, a monoclonal antibody against the tumor-associated disialoganglioside GD2, has activity against neuroblastoma and that such activity is enhanced when ch14.18 is combined with granulocyte–macrophage colony-stimulating factor (GM-CSF) or interleukin-2. We conducted a study to determine whether adding ch14.18, GM-CSF, and interleukin-2 to standard isotretinoin therapy after intensive multimodal therapy would improve outcomes in high-risk neuroblastoma. Methods Patients with high-risk neuroblastoma who had a response to induction therapy and stem-cell transplantation were randomly assigned, in a 1:1 ratio, to receive standard therapy (six cycles of isotretinoin) or immunotherapy (six cycles of isotretinoin and five concomitant cycles of ch14.18 in combination with alternating GM-CSF and interleukin-2). Event-free survival and overall survival were compared between the immunotherapy group and the standard-therapy group, on an intention...

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Anti-GD2 Antibody with GM-CSF, Interleukin-2, and Isotretinoin for Neuroblastoma

Summary Background Patients with squamous non-small-cell lung cancer that is refractory to multiple treatments have poor outcomes. We assessed the activity of nivolumab, a fully human IgG4 PD-1 immune checkpoint inhibitor antibody, for patients with advanced, refractory, squamous non-small-cell lung cancer. Methods We did this phase 2, single-arm trial at 27 sites (academic, hospital, and private cancer centres) in France, Germany, Italy, and USA. Patients who had received two or more previous treatments received intravenous nivolumab (3 mg/kg) every 2 weeks until progression or unacceptable toxic effects. The primary endpoint was the proportion of patients with a confirmed objective response as assessed by an independent radiology review committee. We included all treated patients in the analyses. This study is registered with ClinicalTrials.gov, number NCT01721759. Findings Between Nov 16, 2012, and July 22, 2013, we enrolled and treated 117 patients. 17 (14·5%, 95% CI 8·7–22·2) of 117 patients had an objective response as assessed by an independent radiology review committee. Median time to response was 3·3 months (IQR 2·2–4·8), and median duration of response was not reached (95% CI 8·31–not applicable); 13 (77%) of 17 of responses were ongoing at the time of analysis. 30 (26%) of 117 patients had stable disease (median duration 6·0 months, 95% CI 4·7–10·9). 20 (17%) of 117 patients reported grade 3–4 treatment-related adverse events, including: fatigue (five [4%] of 117 patients), pneumonitis (four [3%]), and diarrhoea (three [3%]). There were two treatment-associated deaths caused by pneumonia and ischaemic stroke that occurred in patients with multiple comorbidities in the setting of progressive disease. Interpretation Nivolumab has clinically meaningful activity and a manageable safety profile in previously treated patients with advanced, refractory, squamous non-small cell lung cancer. These data support the assessment of nivolumab in randomised, controlled, phase 3 studies of first-line and second-line treatment. Funding Bristol-Myers Squibb.

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Activity and safety of nivolumab, an anti-PD-1 immune checkpoint inhibitor, for patients with advanced, refractory squamous non-small-cell lung cancer (CheckMate 063): a phase 2, single-arm trial

Summary Background Cancer survival varies widely between countries. The CONCORD study provides survival estimates for 1·9 million adults (aged 15–99 years) diagnosed with a first, primary, invasive cancer of the breast (women), colon, rectum, or prostate during 1990–94 and followed up to 1999, by use of individual tumour records from 101 population-based cancer registries in 31 countries on five continents. This is, to our knowledge, the first worldwide analysis of cancer survival, with standard quality-control procedures and identical analytic methods for all datasets. Methods To compensate for wide international differences in general population (background) mortality by age, sex, country, region, calendar period, and (in the USA) ethnic origin, we estimated relative survival, the ratio of survival noted in the patients with cancer, and the survival that would have been expected had they been subject only to the background mortality rates. 2800 life tables were constructed. Survival estimates were also adjusted for differences in the age structure of populations of patients with cancer. Findings Global variation in cancer survival was very wide. 5-year relative survival for breast, colorectal, and prostate cancer was generally higher in North America, Australia, Japan, and northern, western, and southern Europe, and lower in Algeria, Brazil, and eastern Europe. CONCORD has provided the first opportunity to estimate cancer survival in 11 states in USA covered by the National Program of Cancer Registries (NPCR), and the study covers 42% of the US population, four-fold more than previously available. Cancer survival in black men and women was systematically and substantially lower than in white men and women in all 16 states and six metropolitan areas included. Relative survival for all ethnicities combined was 2–4% lower in states covered by NPCR than in areas covered by the Surveillance Epidemiology and End Results (SEER) Program. Age-standardised relative survival by use of the appropriate race-specific and state-specific life tables was up to 2% lower for breast cancer and up to 5% lower for prostate cancer than with the census-derived national life tables used by the SEER Program. These differences in population coverage and analytical method have both contributed to the survival deficit noted between Europe and the USA, from which only SEER data have been available until now. Interpretation Until now, direct comparisons of cancer survival between high-income and low-income countries have not generally been available. The information provided here might therefore be a useful stimulus for change. The findings should eventually facilitate joint assessment of international trends in incidence, survival, and mortality as indicators of cancer control. Funding Centers for Disease Control and Prevention (Atlanta, GA, USA), Department of Health (London, UK), Cancer Research UK (London, UK).

https://www.thelancet.com/pdfs/journals/lanonc/PIIS1470-2045(08)70179-7.pdf

Cancer survival in five continents: a worldwide population-based study (CONCORD)

CASS includes a multicenter patient registry and a randomized controlled clinical trial. It is designed to assess the effect of coronary artery bypass surgery on mortality and selected nonfatal end points. From August 1975 to May 1979, 780 patients with stable ischemic heart disease were randomly assigned to receive surgical (n = 390) or nonsurgical (n = 390) treatment and were followed through April 15, 1983. At 5 years, the average annual mortality rate in patients assigned to surgical treatment was 1.1%. The annual mortality rate in those receiving medical therapy was 1.6%. Annual mortality rates in patients with single-, double-, and triple-vessel disease who were in the surgical group were 0.7%, 1.0%, and 1.5%; the corresponding rates in patients in the medical group were 1.4%, 1.2%, and 2.1%. The differences were not statistically significant. Nearly 75% of the patients had entry ejection fractions of at least 0.50. The annual mortality rates in patients in the surgical group in this subgroup with single-, double-, and triple-vessel disease were 0.8%, 0.8%, and 1.2% and corresponding rates in the medical group were 1.1%, 0.6%, and 1.2%. The annual rate of bypass surgery in patients who were initially assigned to receive medical treatment was 4.7%. The excellent survival rates observed both in CASS patients assigned to receive medical and those assigned to receive surgical therapy and the similarity of survival rates in the two groups of patients in this randomized trial lead to the conclusion that patients similar to those enrolled in this trial can safely defer bypass surgery until symptoms worsen to the point that surgical palliation is required.

Coronary artery surgery study (CASS): a randomized trial of coronary artery bypass surgery. Survival data.

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W. S. Lazarus-Barlow

Papers

The natural duration of cancer