Competing risks and cancer-specific mortality: why it matters

An Exploration of Shared Risk Factors for Coronary Artery Disease and Cancer from 109 Traits: The Evidence from Two-Sample Mendelian Randomization Studies

Background

Although observational studies have reported several common biomarkers related to coronary artery disease (CAD) and cancer, there is a shortage of traditional epidemiological data to establish causative linkages. Thus, we conducted a comprehensive two-sample Mendelian randomization (MR) analysis to systematically investigate the causal associations of 109 traits with both CAD and cancer to identify their shared risk and protective factors.

Methods

The genetic association datasets pertaining to exposure and outcomes were reviewed using the most recent and public genome-wide association studies (GWAS). Inverse variance weighting (IVW), weighted median (WM), and MR-Egger strategies were implemented for the MR analyses. The heterogeneity and pleiotropy were measured utilizing leave-one-out sensitivity testing, MR-PRESSO outlier detection, and Cochran's Q test.

Results

The IVW analyses revealed that genetic-predicted mean sphered cell volume (MSCV) is a protective factor for CAD, and weight is a risk factor. MSCV and weight also show similar effects on cancer. Furthermore, our study also identified a set of risk and protective factors unique to CAD and cancer, such as telomere length.

Conclusions

Our Mendelian randomization study sheds light on shared and unique risk and protective factors for CAD and cancer, offering valuable insights that could guide future research and the development of personalized strategies for preventing and treating these two significant health issues.

Colorectal cancer recurrence and its impact on survival after curative surgery: An analysis based on multistate models

AIM

To investigate the usefulness of multistate models (MSM) for determining colorectal cancer (CRC) recurrence rate, to analyse the effect of different factors on tumour recurrence and death, and to assess the impact of recurrence for CRC prognosis.

METHODS

Observational follow-up study of incident CRC cases disease-free after curative resection in 2006-2013 (n = 994). Recurrence and mortality were analyzed with MSM, as well as covariate effects on transition probabilities.

RESULTS

Cumulative incidence of recurrence at 60 months was 13.7%. Five years after surgery, 70.3% of patients were alive and recurrence-free, and 8.4% were alive after recurrence. Recurrence has a negative impact on prognosis, with 5-year CRC-related mortality increasing from 3.8% for those who are recurrence-free 1-year after surgery to 33.6% for those with a recurrence. Advanced stage increases recurrence risk (HR = 1.53) and CRC-related mortality after recurrence (HR = 2.35). CRC-related death was associated with age in recurrence-free patients, and with comorbidity after recurrence. As expected, age≥75 years was a risk factor for non-CRC-related death with (HR = 7.76) or without recurrence (HR = 4.26), while its effect on recurrence risk was not demonstrated.

CONCLUSIONS

MSM allows detailed analysis of recurrence and mortality in CRC. Recurrence has a negative impact on prognosis. Advanced stage was a determining factor for recurrence and CRC-death after recurrence.

Predictors of frequent emergency department visits among hospitalized cancer patients: a comparative cohort study using integrated clinical and administrative data to improve care delivery

BACKGROUND

Frequent emergency department (FED) visits by cancer patients represent a significant burden to the health system. This study identified determinants of FED in recently hospitalized cancer patients, with a particular focus on opioid use.

METHODS

A prospective cohort discharged from surgical/medical units of the McGill University Health Centre was assembled. The outcome was FED use (≥ 4 ED visits) within one year of discharge. Data retrieved from the universal health insurance system was analyzed using Cox Proportional Hazards (PH) model, adopting the Lunn-McNeil approach for competing risk of death.

RESULTS

Of 1253 patients, 14.5% became FED users. FED use was associated with chemotherapy one-year pre-admission (adjusted hazard ratio (aHR) 2.60, 95% CI: 1.80-3.70), ≥1 ED visit in the previous year (aHR: 1.80, 95% CI 1.20-2.80), ≥15 pre-admission ambulatory visits (aHR 1.54, 95% CI 1.06-2.34), previous opioid and benzodiazepine use (aHR: 1.40, 95% CI: 1.10-1.90 and aHR: 1.70, 95% CI: 1.10-2.40), Charlson Comorbidity Index ≥ 3 (aHR: 2.0, 95% CI: 1.2-3.4), diabetes (aHR: 1.60, 95% CI: 1.10-2.20), heart disease (aHR: 1.50, 95% CI: 1.10-2.20) and lung cancer (aHR: 1.70, 95% CI: 1.10-2.40). Surgery (cardiac (aHR: 0.33, 95% CI: 0.16-0.66), gastrointestinal (aHR: 0.34, 95% CI: 0.14-0.82) and thoracic (aHR: 0.45, 95% CI: 0.30-0.67) led to a decreased risk of FED use.

CONCLUSIONS

Cancer patients with higher co-morbidity, frequent use of the healthcare system, and opioid use were at increased risk of FED use. High-risk patients should be flagged for preventive intervention.

Using administrative healthcare data to evaluate drug repurposing opportunities for cancer: the possibility of using beta-blockers to treat breast cancer

Introduction: Cancer registries and hospital electronic medical records are commonly used to investigate drug repurposing candidates for cancer. However, administrative data are often more accessible than data from cancer registries and medical records. Therefore, we evaluated if administrative data could be used to evaluate drug repurposing for cancer by conducting an example study on the association between beta-blocker use and breast cancer mortality. Methods: A retrospective cohort study of women aged ≥50 years with incident breast cancer was conducted using a linked dataset with statewide hospital admission data and nationwide medication claims data. Women receiving beta blockers and first-line anti-hypertensives prior to and at diagnosis were compared. Breast cancer molecular subtypes and metastasis status were inferred by algorithms from commonly prescribed breast cancer antineoplastics and hospitalization diagnosis codes, respectively. Subdistribution hazard ratios (sHR) and corresponding 95% confidence intervals (CIs) for breast cancer mortality were estimated using Fine and Gray's competing risk models adjusted for age, Charlson comorbidity index, congestive heart failure, myocardial infraction, molecular subtype, presence of metastasis at diagnosis, and breast cancer surgery. Results: 2,758 women were hospitalized for incident breast cancer. 604 received beta-blockers and 1,387 received first-line antihypertensives. In total, 154 breast cancer deaths were identified over a median follow-up time of 2.7 years. We found no significant association between use of any beta-blocker and breast-cancer mortality (sHR 0.86, 95%CI 0.58-1.28), or when stratified by beta-blocker type (non-selective, sHR 0.42, 95%CI 0.14-1.25; selective, sHR 0.95, 95%CI 0.63-1.43). Results were not significant when stratified by molecular subtypes (e.g., triple negative breast cancer (TNBC), any beta blocker, sHR 0.16, 95%CI 0.02-1.51). Discussion: It is possible to use administrative data to explore drug repurposing opportunities. Although non-significant, an indication of an association was found for the TNBC subtype, which aligns with previous studies using registry data. Future studies with larger sample size, longer follow-up are required to confirm the association, and linkage to clinical data sources are required to validate our methodologies.

Risk of Colorectal Cancer and Colorectal Cancer Mortality Beginning Ten Years after a Negative Colonoscopy, among Screen-Eligible Adults 76 to 85 Years Old

BACKGROUND

Few empirical data are available to inform older adults' decisions about whether to screen or continue screening for colorectal cancer based on their prior history of screening, particularly among individuals with a prior negative exam.

METHODS

Using a retrospective cohort of older adults receiving healthcare at three Kaiser Permanente integrated healthcare systems in Northern California (KPNC), Southern California (KPSC), and Washington (KPWA), we estimated the cumulative risk of colorectal cancer incidence and mortality among older adults who had a negative colonoscopy 10 years earlier, accounting for death from other causes.

RESULTS

Screen-eligible adults ages 76 to 85 years who had a negative colonoscopy 10 years earlier were found to be at a low risk of colorectal cancer diagnosis, with a cumulative incidence of 0.39% [95% CI, 0.31%-0.48%) at 2 years that increased to 1.29% (95% CI, 1.02%-1.61%) at 8 years. Cumulative mortality from colorectal cancer was 0.04% (95% CI, 0.02%-0.08%) at 2 years and 0.46% (95% CI, 0.30%-0.70%) at 8 years.

CONCLUSIONS

These low estimates of cumulative colorectal cancer incidence and mortality occurred in the context of much higher risk of death from other causes.

IMPACT

Knowledge of these results could bear on older adults' decision to undergo or not undergo further colorectal cancer screening, including choice of modality, should they decide to continue screening. See related commentary by Lieberman, p. 6.

Trends in hospitalization and in-hospital mortality rates among patients with lung cancer in Spain between 2010 and 2020

BACKGROUND

Lung cancer is the third most frequent tumor and the main cause of death by tumor in Spain. Although the incidence and mortality are still significantly higher in men than in women, the disparity between the sexes is decreasing. The objective of this study was to analyze the evolution of lung cancer hospitalization and in-hospital mortality rates in Spain from 2010 to 2020.

METHODS

The reports of the Minimum Basic Data Set (MBDS) at hospital discharge were used to retrospectively analyze the data of all patients with a primary diagnosis of lung cancer, according to the International Classification of Diseases (ICD-9-CM and ICD-10-CM).

RESULTS

Between 2010 and 2020, there were 315,263 hospitalizations and 70,490 deaths from lung cancer in Spain, the majority (~ 80%) in men. Overall, the rates of hospitalization and in-hospital mortality from lung cancer showed a downward trend throughout the period, although the number of new diagnoses and the absolute number of deaths in women increased. Due to the aging of the population, the degree of comorbidity in patients with lung cancer, although it remains relatively low, is also on the rise.

CONCLUSION

Lung cancer represents a substantial clinical and economic burden for patients and for the National Health System, so it is necessary to promote primary prevention campaigns, as well as to develop more effective population screening measures to detect cancers early and increase the patient survival.

Improving the Lung Cancer Clinical Trial Development by Incorporating Competing Risk Factors

Introduction

Distinct from other diseases, as cancer progresses, both the symptoms and treatments evolve, resulting in a complex, time-dependent relationship. Many competing risk factors influence the outcome of cancer. An improved method was used to evaluate the data from 6 non-small-cell lung cancer (NSCLC) clinical trials combined in our center since 2016 to deal with the bias caused by competing risk factors. Material and Methods. Data of 118 lung cancer patients were collected from 2016 to 2020. Fine and Gray's model for competing risk was used to evaluate survival of different treatment group compares with the classic survival analysis model.

Results

Immunotherapy had better progression-free survival than chemotherapy. (HR: 0.62, 95% CI: 0.41-0.95, p = 0.0260). However, there were no significant differences in patients who withdrew due to treatment-related adverse events from different groups. (Z = 0.0508, p = 0.8217). The PD-1/PD-L1 inhibitors in our study did not significantly improve overall survival compared with chemotherapy (HR:0.77, 95% CI:0.48-1.24, p = 0.2812), estimated 1-year overall survival rates were 55% and 46%, and 3-year overall survival rates were 17% and 10%, respectively.

Conclusion

When the outcome caused by competing risk exists, the corresponding competing risk model method should be adopted to eliminate the bias caused by the classic survival analysis.

Competing Causes of Death in Older Adults with Thyroid Cancer

Background: Understanding the impact of comorbidities and competing risks of death when caring for older adults with thyroid cancer is key for personalized management. The objective of this study was to determine whether older adults with thyroid cancer are more likely to die from thyroid cancer or other etiologies, and determine patient factors associated with each. Methods: The Surveillance, Epidemiology, and End Results (SEER)-Medicare database was used to identify patients aged ≥66 years diagnosed with thyroid cancer (papillary, follicular, Hürthle cell, medullary, anaplastic, and other) between 2000 and 2015 (median follow-up, 50 months). We analyzed time to event (i.e., death from other causes or death from thyroid cancer) using cumulative incidence functions. Competing risk hazards regression was used to determine the association between patient (e.g., age at diagnosis and specific comorbidities) and tumor characteristics (e.g., SEER stage) with two competing mortality outcomes: death from other causes and death from thyroid cancer. Results: Of 21,509 patients with a median age of 72 years (range 66-106), 4168 (19.4%) died of other causes and 2644 (12.3%) died of thyroid cancer during the study period. For differentiated thyroid cancer patients, likelihood of dying from other causes exceeds likelihood of dying from thyroid cancer, whereas the opposite is true for anaplastic thyroid cancer. For medullary thyroid cancer, after 6.25 years patients are more likely to die from other etiologies than thyroid cancer. Using competing risks hazards regression, male sex (hazards ratio [HR] 1.47; 95% confidence interval [CI 1.37-1.57]), black race (HR 1.30; CI [1.16-1.46]), and comorbidities (e.g., heart disease, HR 1.34; CI [1.25-1.44]; chronic lower respiratory disease, HR 1.25; CI [1.17-1.34]) were associated with death from other causes. Tumor characteristics such as histology, tumor size, and stage correlated with death from thyroid cancer (e.g., distant SEER stage compared with localized, HR 12.65; CI [10.91-14.66]). Conclusions: The clinical context, including patients' specific comorbidities, should be considered when diagnosing and managing thyroid cancer. Our findings can be used to develop decision models that account for competing causes of death, as an aid for clinical decision making.

Immune checkpoint blockade in the treatment of advanced non-small cell lung cancer - predictors of response and impact of previous radiotherapy

BACKGROUND

The implementation of immune checkpoint inhibitors (ICI) into the standard care of advanced non-small cell lung cancer (NSCLC) has improved prognosis for this group of patients. However, long-term survival is rare. The aim of the study was to identify predictors of response and, especially, to investigate the impact radiotherapy might have on duration of response.

MATERIAL AND METHODS

The association between pretreatment patient/tumor characteristics and progression-free survival (PFS), overall survival (OS), and lung cancer-specific survival was investigated in 78 patients receiving an ICI as ≥2nd line treatment for advanced NSCLC, using Cox regression analysis. Due to competing risk, cause-specific deaths were also examined with cumulative incidence plots.

RESULTS

Median OS was 12.6 months (95% CI 7.8-18.2) and median PFS 4.1 months (95% CI 3.0-6.2), after median follow-up time of 49.7 months (range 20.9-51.5). Increasing CRP and neutrophil/lymphocyte ratio (NLR), were associated with poor PFS (CRP: HR 1.49, 95% CI 1.12-1.98; NLR: HR 1.59, 95% CI 1.22-1.85) and OS (CRP: HR 1.94, 95% CI 1.47-2.56; NLR: HR 1.54, 95% CI 1.27-1.87). Radiotherapy prior to immunotherapy was not significantly associated with patient outcome. However, when the dataset was split at 6 months of follow-up, to be able to identify early and late predictors of prognosis, we found that patients receiving radiotherapy <6 months prior to immunotherapy had better PFS (HR: 0.27, 95% CI 0.09-0.84) and lung cancer-specific survival (HR: 0.41, 95% CI 0.18-0.95) after the first 6 months of follow-up, while increasing CRP (PFS: HR1.61, 95% CI 1.21-2.14; OS: HR2.04, 95% CI 1.51-2.74) and NLR (PFS: HR 1.57, 95% CI 1.29-1.91; OS: HR 1.63, 95% CI 1.35-1.97) were predictors of poor short-term prognosis.

CONCLUSIONS

Radiotherapy may be of importance to achieve a long-lasting response to immunotherapy, while indicators of systemic inflammation can help in identifying patients with poor short-term prognosis.

Racial Disparities in the Incidence and Survival of Spinal Meningioma

Objective:

Race is a significant prognostic factor in various cancers, including the breast. Its prognostic association with spinal meningioma has not been established, although the incidence of spinal meningioma varies by race. In this retrospective cohort study, we aimed to investigate the association of race with the incidence and survival of spinal meningioma among a large population sample.

Materials and Methods:

A comprehensive search was done in the surveillance, epidemiology, and end results database between 2000 and 2016 to identify patients with spinal meningioma. Overall and race-specific incidence were calculated. The effect of race on overall survival among these patients was determined with Kaplan–Meier curve and Cox proportional hazard models.

Results:

Of 3502 spinal meningioma patients, 82.6% were Caucasian, 7.7% were African-American, 8.8% were Asian/Pacific Islander and 0.7% were American Indian/Alaska Native. The overall age-adjusted incidence was 0.239/100,000; it was highest among Caucasian (0.249) and lowest among American Indian/Alaska Native patients (0.137). There was a race effect in overall survival in the unadjusted analysis with the worst overall survival reported for Caucasian patients, and the best reported for American Indian/Alaska Native patients. However, this relationship was insignificant in the adjusted analysis.

Conclusions:

Race was not significantly associated with overall survival among these patients. Future studies should use spinal-meningioma-specific survival as outcome to see whether there is a racial difference in survival.

Competing Risks of Cancer and Non-Cancer Mortality When Accompanied by Lifestyle-Related Factors-A Prospective Cohort Study in Middle-Aged and Older Adults

Background

The study aimed to identify the association between the lifestyle-related factors and the cancer-specific, or non-cancer-specific mortality, when accompanied by a competing risk. Two statistical methods were applied, i.e., cause-specific hazard (CSH), and sub-distribution hazard ratio (SHR). Their respective key advantages, relative to the actual study design, were addressed, as was overall application potential.

Methods

Source data from 4,584 residents (34.2% men), aged 45–64 years, were processed using two different families of regression models, i.e., CSH and SHR; principal focus upon the impact of lifestyle-related factors on the competing risk of cancer and non-cancer mortality. The results were presented as hazard ratios (HR) with 95% confidence intervals (95% CI).

Results

Age, smoking status, and family history of cancer were found the leading risk factors for cancer death; the risk of non-cancer death higher in the elderly, and smoking individuals. Non-cancer mortality was strongly associated with obesity and hypertension. Moderate to vigorous physical activity decreased the risk of death caused by cancer and non-cancer causes.

Conclusions

Specific, lifestyle-related factors, instrumental in increasing overall, and cancer-specific mortality, are modifiable through health-promoting, individually pursued physical activities. Regular monitoring of such health-awareness boosting pursuits seems viable in terms of public health policy making.

Impact of pre-existing cardiovascular disease on treatment patterns and survival outcomes in patients with lung cancer

Background

Baseline cardiovascular disease (CVD) can impact the patterns of treatment and hence the outcomes of patients with lung cancer. This study aimed to characterize treatment trends and survival outcomes of patients with pre-existing CVD prior to their diagnosis of lung cancer.

Methods

We conducted a retrospective, population-based cohort study of patients with lung cancer diagnosed from 2004 to 2015 in a large Canadian province. Multivariable logistic regression and Cox regression models were constructed to determine the associations between CVD and treatment patterns, and its impact on overall (OS) and cancer-specific survival (CSS), respectively. A competing risk multistate model was developed to determine the excess mortality risk of patients with pre-existing CVD.

Results

A total of 20,689 patients with lung cancer were eligible for the current analysis. Men comprised 55%, and the median age at diagnosis was 70 years. One-third had at least one CVD, with the most common being congestive heart failure in 15% of patients. Pre-existing CVD was associated with a lower likelihood of receiving chemotherapy (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.48–0.58; P < .0001), radiotherapy (OR, 0.76; 95% CI, 0.7–0.82; P < .0001), and surgery (OR, 0.56; 95% CI, 0.44–0.7; P < .0001). Adjusting for measured confounders, the presence of pre-existing CVD predicted for inferior OS (hazard ratio [HR], 1.1; 95% CI, 1.1–1.2; P < .0001) and CSS (HR, 1.1; 95% CI, 1.1–1.1; P < .0001). However, in the competing risk multistate model that adjusted for baseline characteristics, prior CVD was associated with increased risk of non-cancer related death (HR, 1.48; 95% CI, 1.33–1.64; P < 0.0001) but not cancer related death (HR, 0.98; 95% CI, 0.94–1.03; P = 0.460).

Conclusions

Patients with lung cancer and pre-existing CVD are less likely to receive any modality of cancer treatment and are at a higher risk of non-cancer related deaths. As effective therapies such as immuno-oncology drugs are introduced, early cardio-oncology consultation may optimize management of lung cancer.

Optimizing the measurement of comorbidity for a South Australian colorectal cancer population using administrative data

RATIONALE AND OBJECTIVES

In epidemiological research, it is essential to account for the confounding effects of factors such as age, stage, and comorbidity for accurate prediction of cancer outcomes. There are several internationally developed and commonly used comorbidity indices. However, none are regarded as the gold-standard method. This study will assess and compare the predictive validity of established indices for use in a South Australian (SA) colorectal cancer (CRC) population against a local index. Furthermore, the prognostic influence of comorbidity on survival is investigated.

METHODS

A population-based study of patients diagnosed with CRC from 2003 to 2012 and linked to in-hospital data to retrieve comorbidity information was conducted. The predictive performance of established indices, Charlson comorbidity index (CCI), National Cancer Institute comorbidity index (NCI), Elixhauser comorbidity index (ECI), and C3 index was evaluated using the Fine and Gray competing risk regression and reported using measures of calibration and discrimination, area under the curve (AUC), and Brier score. Furthermore, to identify the optimal index, a local CRC comorbidity index (CRCCI) was also developed and its performance compared with the established indices.

RESULTS

Comorbidity models adjusted for age, sex, and stage showed that all indices were good predictors of mortality as measured by the AUC (CCI: 0.738, NCI: 0.742, ECI: 0.733, C3: 0.739). CRCCI had similar mortality prediction as established indices (CRCCI: 0.747). There was a significant increase in cumulative risk of noncancer and CRC-specific mortality with increase in comorbidity scores. The two most prevalent comorbidities were hypertension and diabetes.

CONCLUSIONS

The existing indices are still valid for adjusting for comorbidity and accurately predicting mortality in an SA CRC population. Internationally developed indices are preferred when policymakers and researchers wish to compare local study results with those of studies (national and international) that have used these indices. Comorbidity is a predictor of mortality and should be considered when assessing CRC survival.

Predictors of survival trajectories among women with epithelial ovarian cancer

OBJECTIVE

Although ovarian cancer is a deadly disease, approximately a third of women survive ≥9 years after diagnosis. The factors associated with achieving long-term survival are not well understood. In this study, data from the Surveillance, Epidemiology, and End Results (SEER) program were used to determine predictors of survival trajectories among women with epithelial ovarian cancer and across histotype (high-grade serous carcinoma (HGSC) and non-HGSC).

METHODS

Data on 35,868 women diagnosed with epithelial ovarian cancer in 2004-2016 were extracted from SEER. Extended Cox proportional hazards regression was used to estimate overall and histotype-specific associations between patient and tumor characteristics and all-cause mortality within each survival time (t) interval (t < 3, 3 ≤ t < 6, 6 ≤ t < 9, and 9 ≤ t < 13 years).

RESULTS

Age at diagnosis, marital status, race/ethnicity, stage, and surgery were more strongly associated with mortality in the short-term survival period, and these associations waned with increasing survival time. Exceptions to this pattern were age >70 years at diagnosis, where a high risk of mortality was observed in both the t < 3 and t ≥ 9 year time periods, and non-Hispanic Asian/Pacific Islanders, where a more pronounced inverse association with mortality was observed in t ≥ 9 years after diagnosis. Similar associations were observed for HGSC, although the waning effect was not apparent for most characteristics. Mortality associations for non-HGSC were more pronounced for stage and race/ethnicity, primarily for non-Hispanic Asian/Pacific Islanders.

CONCLUSIONS

Most patient and tumor characteristics were more strongly associated with mortality in the years following diagnosis, but have declining impact with increasing survival time. Given this waning effect, it is critical to identify factors impacting risk of mortality as ovarian cancer patients advance through the survival trajectory.

Minimally Invasive Lobectomy Is Associated With Lower Noncancer-specific Mortality in Elderly Patients: A Propensity Score Matched Competing Risks Analysis

OBJECTIVE

To investigate cancer- and noncancer-specific mortality following lobectomy by minimally invasive surgery (MIS) versus open thoracotomy in elderly patients with nonsmall cell lung cancer (NSCLC).

BACKGROUND

Two-thirds of patients with NSCLC are ≥65 years of age. As age increases, the risk of competing events, such as noncancer death, also increases.

METHODS

Elderly patients (≥65 yrs of age) who have undergone curative-intent lobectomy for stage I-III NSCLC without induction therapy (2002-2013) were included (n=1,303). Of those, 607 patients had undergone MIS and 696 had undergone thoracotomy. Propensity-score matching was performed to identify pairs of thoracotomy and MIS patients with comparable clinical characteristics (eg, year of surgery, comorbidities, and pulmonary function). Association between surgical approach (MIS vs thoracotomy) and lung cancer-specific and noncancer-specific cumulative incidence of death (CID) was analyzed using competing risks approach.

RESULTS

Following propensity score matching of patients who had undergone thoracotomy (n=338) versus MIS (n=338), MIS was associated with shorter length of stay (P <0.001), lower noncancer-specific 1-year mortality (P=0.027), and lower noncancer-specific CID (P=0.014) compared with thoracotomy; there was no difference in lung cancer-specific CID between surgical approaches. On multivariable analysis, thoracotomy was a significant risk factor for noncancer-specific death (subhazard ratio 2.45, 95% CI 1.18-5.06, P=0.016) independent of age, sex, and diffusion capacity of the lungs for carbon monoxide.

CONCLUSION

In a propensity score-matched cohort, multivariable analysis has indicated that lobectomy performed by MIS is associated with lower incidence of noncancer-specific mortality compared with lobectomy performed by open thoracotomy in elderly patients with NSCLC.

Is the risk of cancer in Australia overstated? The importance of competing mortality for estimating lifetime risk

OBJECTIVES

To calculate lifetime risks of cancer diagnosis and cancer-specific death, adjusted for competing mortality, and to compare these estimates with the corresponding risks published by the Australian Institute of Health and Welfare (AIHW).

DESIGN, SETTING

Analysis of publicly available annual AIHW data on age-specific cancer incidence and mortality - for breast cancer, colorectal cancer, prostate cancer, melanoma of the skin, and lung cancer - and all-cause mortality in Australia, 1982-2013.

OUTCOME MEASURES

Lifetime risks of cancer diagnosis and mortality (to age 85), adjusted for competing mortality.

RESULTS

During 1982-2013, AIHW estimates were consistently higher than our competing mortality-adjusted estimates of lifetime risks of diagnosis and death for all five cancers. Differences between AIHW and adjusted estimates declined with time for breast cancer, prostate cancer, colorectal cancer, and lung cancer (for men only), but remained steady for lung cancer (women only) and melanoma of the skin. In 2013, the respective estimated lifetime risks of diagnosis (AIHW and adjusted) were 12.7% and 12.1% for breast cancer, 18.7% and 16.2% for prostate cancer, 9.0% and 7.0% (men) and 6.4% and 5.5% (women) for colorectal cancer, 7.5% and 6.0% (men) and 4.4% and 4.0% (women) for melanoma of the skin, and 7.6% and 5.8% (men) and 4.5% and 3.9% (women) for lung cancer.

CONCLUSION

The method employed in Australia to calculate the lifetime risks of cancer diagnosis and mortality overestimates these risks, especially for men.

Expansion of the Concept of Micropapillary Adenocarcinoma to Include a Newly Recognized Filigree Pattern as Well as the Classical Pattern Based on 1468 Stage I Lung Adenocarcinomas

INTRODUCTION

The classical micropapillary (MIP) pattern is defined in the 2015 WHO classification as tumor cells growing in papillary tufts forming florets that lack fibrovascular cores, and it is associated with poor prognosis. We observed a novel pattern that we termed a filigree MIP pattern and investigated its relationship with the classical MIP pattern.

METHODS

Filigree pattern was defined as tumor cells growing in delicate, lace-like, narrow stacks of cells without fibrovascular cores. We required at least three piled-up nuclei from the alveolar wall basal layer, with a breadth of up to three cells across. To assess the relationship of the filigree pattern with the classical MIP pattern, we documented their frequencies in the context of the clinical and pathologic characteristics of 1468 stage I invasive adenocarcinomas, including survival analysis using cumulative incidence of recurrence by competing risks.

RESULTS

We observed the filigree MIP pattern in 35% of cases. By including the filigree pattern as an MIP pattern, we identified 57 more MIP predominant cases in addition to the previously diagnosed 87 MIP predominant adenocarcinomas. These 57 cases were reclassified from papillary (n = 37), acinar (n = 16), and solid (n = 4) predominant adenocarcinoma, respectively. Of the 144 MIP predominant adenocarcinomas, the filigree predominant MIP pattern (n = 78) showed a poor prognosis like the classical predominant MIP pattern (n = 66) (p = 0.464). In addition, like the classical MIP pattern (p = 0.010), even a small amount (≥5%) of filigree MIP pattern was significantly associated with worse cumulative incidence of recurrence (p = 0.001) in multivariable analysis.

CONCLUSION

The frequent association with the classical MIP pattern and the similar poor prognosis supports inclusion of the filigree pattern in the MIP pattern subtype.

Misclassification of the actual causes of death and its impact on analysis: A case study in non-small cell lung cancer

OBJECTIVES

Cumulative incidence of lung cancer deaths (LC-CID) is an important metric to understand cancer prognosis and to determine treatment options. However, credible estimates of LC-CID rely on accurate cause-of-death coding in death certificates. Results from lung cancer screening trials estimated 15% under-reporting and 1% over-reporting of lung cancer deaths due to misclassification. This study investigated the impact of cause-of-death misclassification on the estimation of LC-CID.

MATERIALS AND METHODS

Patients with stage I/II non-small cell lung cancer (NSCLC) from the Surveillance, Epidemiology, and End Results registry were included. LC-CID was estimated using the competing-risk approach in two ways: (1) reporting observed estimates that ignore potential cause-of-death misclassification and (2) correcting for plausible misclassification rates reported in the literature (15% under-reporting and 1% over-reporting). Bias was quantified as the difference between observed and corrected 10-year LC-CIDs: positive values indicated that observed LC-CID overestimated true LC-CID, whereas negative values indicated the opposite.

RESULTS

Among 66,179 patients, the impact of over-reporting on 10-year LC-CID was negligible across all age groups. In contrast, under-reporting resulted in substantial underestimation of 10-year LC-CID. The biases increased as age increased due to higher LC-CIDs: 10-year LC-CIDs among stage I patients 18-44, 45-59, 60-74 and ≥75 years were 25%, 32%, 41%, and 50%, respectively, and the corresponding biases given the plausible misclassification rates were -4.4%, -5.6%, -7.1%, and -8.6%. Because the observed LC-CIDs among patients with stage II disease were higher than those with stage I disease, the biases were greater among stage II patients, up to -12.5% in the oldest age group.

CONCLUSIONS

In lung cancer, LC-CID may be severely underestimated due to under-reporting of lung cancer deaths, particularly among older patients or those with late-stage disease. Future studies that involve such subpopulations should present the corrected LC-CIDs based on plausible misclassification rates alongside the observed LC-CIDs.

Statistical issues and methods in designing and analyzing survival studies

BACKGROUND

Cancer studies that are designed for early detection and screening, or used for identifying prognostic factors, or assessing treatment efficacy and health outcome are frequently assessed with survival or time-to-event outcomes. These studies typically require specific methods of data analysis. Appropriate statistical methods in the context of study design and objectives are required for obtaining reliable results and valid inference. Unfortunately, variable methods for the same study objectives and dubious reporting have been noticed in the survival analysis of oncology research. Applied researchers often face difficulties in selecting appropriate statistical methods due to the complex nature of cancer studies.

RECENT FINDINGS

In this report, we describe briefly major statistical issues along with related challenges in planning, designing, and analyzing of survival studies. For applied researchers, we provided flow charts for selecting appropriate statistical methods. Various available statistical procedures in common statistical packages for applying survival analysis were classified according to different objectives of the study. In addition, an illustration of the statistical analysis of some common types of time-to-event outcomes was shown with STATA codes.

CONCLUSIONS

We anticipate that this review article assists oncology researchers in understanding important statistical concepts involved in survival analysis and appropriately select the statistical approaches for survival analysis studies. Overall, the review may help in improving designing, conducting, analyzing, and reporting of data in survival studies.

Procedure-Specific Risk Prediction for Recurrence in Patients Undergoing Lobectomy or Sublobar Resection for Small (≤2 cm) Lung Adenocarcinoma: An International Cohort Analysis

INTRODUCTION

This work was performed to develop and validate procedure-specific risk prediction for recurrence following resection for early-stage lung adenocarcinoma (ADC) and investigate risk prediction utility in identifying patients who may benefit from adjuvant chemotherapy (ACT).

METHODS

In patients who underwent resection for small (≤2 cm) lung ADC (lobectomy, 557; sublobar resection, 352), an association between clinicopathologic variables and risk of recurrence was assessed by a competing risks approach. Procedure-specific risk prediction was developed based on multivariable regression for recurrence. External validation was conducted using cohorts (N = 708) from Japan, Taiwan, and Germany. The accuracy of risk prediction was measured using a concordance index. We applied the lobectomy risk prediction approach to a propensity score-matched cohort of patients with stage II-III disease (n = 316, after matching) with or without ACT and compared lung cancer-specific survival between groups among low- or high-risk scores.

RESULTS

Micropapillary pattern, solid pattern, lymphovascular invasion, and necrosis were involved in the risk prediction following lobectomy, and micropapillary pattern, spread through air spaces, lymphovascular invasion, and necrosis following sublobar resection. Both internal and external validation showed good discrimination (concordance index in lobectomy and sublobar resection: internal, 0.77 and 0.75, respectively; and external, 0.73 and 0.79, respectively). In the stage II-III propensity score-matched cohort, among high-risk patients, ACT significantly reduced the risk of lung cancer-specific death (subhazard ratio 0.43, p = 0.001), but not among low-risk patients.

CONCLUSIONS

Procedure-specific risk prediction for patients with resected small lung ADC can be used to better prognosticate and stratify patients for further interventions.

Pathologic Assessment After Neoadjuvant Chemotherapy for NSCLC: Importance and Implications of Distinguishing Adenocarcinoma From Squamous Cell Carcinoma

INTRODUCTION

Major pathologic response after neoadjuvant chemotherapy (NAC) for NSCLC has been defined as 10% or less residual viable tumor without distinguishing between histologic types. We sought to investigate whether the optimal cutoff percentage of residual viable tumor for predicting survival differs between lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC).

METHODS

Tumor slides from 272 patients treated with NAC and surgery for clinical stage II-III NSCLC (ADC, n = 192; SCC, n = 80) were reviewed. The optimal cutoff percentage of viable tumor for predicting lung cancer-specific cumulative incidence of death (LC-CID) was determined using maximally selected rank statistics. LC-CID was analyzed using a competing-risks approach. Overall survival was evaluated using Kaplan-Meier methods and Cox proportional hazard analysis.

RESULTS

Patients with SCC had a better response to NAC (median percentage of viable tumor: SCC versus ADC, 40% versus 60%; p = 0.027). Major pathologic response (≤10% viable tumor) was observed in 26% of SCC cases versus 12% of ADC cases (p = 0.004). The optimal cutoff percentage of viable tumor for LC-CID was 10% for SCC and 65% for ADC. On multivariable analysis, viable tumor 10% or less was an independent factor for better LC-CID (p = 0.035) in patients with SCC; in patients with ADC, viable tumor 65% or less was a factor for better LC-CID (p = 0.033) and overall survival (p = 0.050).

CONCLUSIONS

In response to NAC, the optimal cutoff percentage of viable tumor for predicting survival differs between ADC and SCC. Our findings have implications for the pathologic assessment of resected specimens, especially in upcoming clinical trials design.