Patterns of age disparities in colon and lung cancer survival: a systematic narrative literature review

Epidemiology of Cancer in Older Adults: A Systematic Review

PURPOSE OF REVIEW

What are the prevalence, incidence and mortality rates of cancer among individuals aged 60 or older on a national, regional, and global scale? What factors affect differences in cancer survival between older and younger adults?

RECENT FINDINGS

The epidemiological literature on cancer in older adults, particularly in low- and middle-income countries (LMICs) and that focusing on the oldest adults, is expanding. These studies consistently show increasing global cancer incidence rates in older populations. Recent research also highlights a widening survival gap between middle-aged and older adults, with the stage at diagnosis being the primary driver. More research is needed to describe the cancer burden in older adults, especially focusing on the oldest population and LMICs, to better understand global healthcare challenges. Additionally, further exploring patient-related, clinical, and tumour-related factors which drive age-related survival differences could improve cancer outcomes in older adults.

Where are the inequalities in ovarian cancer care in a country with universal healthcare? A systematic review and narrative synthesis

INTRODUCTION

Patients diagnosed with ovarian cancer from more deprived areas may face barriers to accessing timely, quality healthcare. We evaluated the literature for any association between socioeconomic group, treatments received and hospital delay among patients diagnosed with ovarian cancer in the United Kingdom, a country with universal healthcare.

METHODS

We searched MEDLINE, EMBASE, CINAHL, CENTRAL, SCIE, AMED, PsycINFO and HMIC from inception to January 2023. Forward and backward citation searches were conducted. Two reviewers independently reviewed titles, abstracts, and full-text articles. UK-based studies were included if they reported socioeconomic measures and an association with either treatments received or hospital delay. The inclusion of studies from one country ensured greater comparability. Risk of bias was assessed using the QUIPS tool, and a narrative synthesis was conducted. The review is reported to PRISMA 2020 and registered with PROSPERO [CRD42022332071].

RESULTS

Out of 2876 references screened, ten were included. Eight studies evaluated treatments received, and two evaluated hospital delays. We consistently observed socioeconomic inequalities in the likelihood of surgery (range of odds ratios 0.24-0.99) and chemotherapy (range of odds ratios 0.70-0.99) among patients from the most, compared with the least, deprived areas. There were no associations between socioeconomic groups and hospital delay.

POLICY SUMMARY

Ovarian cancer treatments differed between socioeconomic groups despite the availability of universal healthcare. Further research is needed to understand why, though suggested reasons include patient choice, health literacy, and financial and employment factors. Qualitative research would provide a rich understanding of the complex factors that drive these inequalities.

Cancer survival analysis on population-based cancer registry data in Zhejiang Province, China (2018-2019)

Objective

This is a comprehensive overview of long-term cancer survival in Zhejiang Province, China. Hybrid analysis, a combination of cohort and period analysis, has been proposed to derive up-to-date cancer survival estimates. Using this approach, we aimed to timely and accurately analyze the 5-year relative survival (RS) and net survival (NS) in cancer registries of Zhejiang Province, China.

Methods

A total of 255,725 new cancer cases diagnosed during 2013-2017 were included in 14 cancer registries in Zhejiang Province, China, with a follow-up on vital status until the end of 2019. The hybrid analysis was used to calculate the 5-year RS and 5-year NS during 2018-2019 for overall and stratifications by sex, cancer type, region, and age at diagnosis.

Results

During 2018-2019, the age-standardized 5-year RS and NS for overall cancer in Zhejiang was 47.5% and 48.6%, respectively. The age-standardized 5-year RS for cancers of women (55.4%) was higher than that of men (40.0%), and the rate of urban areas (49.7%) was higher than that of rural areas (43.1%). The 5-year RS declined along with age, from 84.4% for ages <45 years to 23.7% for ages >74 years. Our results of the RS and NS showed the similar trend and no significant difference. The top five cancers with top age-standardized 5-year RS were thyroid cancer (96.0%), breast cancer (84.3%), testicular cancer (79.9%), prostate cancer (77.2%), and bladder cancer (70.6%), and the five cancers with the lowest age-standardized 5-year RS were pancreatic cancer (6.0%), liver cancer (15.6%), gallbladder cancer (17.1%), esophageal cancer (22.7%), and leukemia (31.0%).

Conclusions

We reported the most up-to-date 5-year cancer RS and NS in Zhejiang Province, China for the first time, and found that the 5-year survival for cancer patients in Zhejiang during 2018-2019 was relatively high. The population-based cancer registries are recognized as key policy tools that can be used to evaluate both the impact of cancer prevention strategies and the effectiveness of health systems.

Prognostic relevance of sidedness in older patients with colon cancer: A review and pooled analysis of 227,218 patients

Age is a major risk factor for sporadic colon cancer (CC). In the general population, the side of the tumor (right versus left) shows a possible significant prognostic effect, with right tumors displaying the worst outcome due to biological differences. However, little is known about the role of sidedness in the older population. We conducted a pooled analysis of observational and prospective studies to confirm or reject the hypothesis that side is a prognostic variable, even in older patients with CC. Using the terms ("colorectal" or "colon") and ("cancer" or "carcinoma") and ("elderly" or "older" or "65 years" or "70 years" or "75 years") and ("side" or "site" or "right" or "left"), we searched PubMed, Embase, and the Cochrane Library through January 2023. We selected studies in the English language to compare the prognosis of left versus right CC in older patients (with a lower age limit of 65 years). The primary endpoint was overall survival (OS). Hazard ratios (HRs) for OS with relative 95% confidence intervals (CIs) were extracted from each study. Summary HRs were calculated using random- or fixed-effects models, depending on the heterogeneity of the included studies. The review process led to the inclusion of 13 articles. The studies reported the OS data for a total of 227,218 patients with CC. The CC side was not independently associated with mortality risk in older CC patients (HR 0.97; 95% CI 0.9-1.04; p = 0.34). High heterogeneity was observed in the main analysis (P < 0.01; I2 = 85%). In conclusion, our analysis shows that the tumor being on the left or right side in older patients with CC has no significant role in the risk of overall death. These data support the use of other parameters, such as stage, biology, comorbidities, and life expectancy, to decide on treatment and the prolongation of screenings until a patient's latest years.

Age-related differences in colon and rectal cancer survival by stage, histology, and tumour site: An analysis of United States SEER-18 data

Age-related differences in colon and rectal cancer survival have been observed, even after accounting for differences in background mortality. To determine how stage, tumour site, and histology contribute to these differences, we extracted age-specific one-year relative survival ratio (RS) stratified by these factors. We used colon and rectal cancer cases diagnosed between 2012 and 2016 from 18 United States Surveillance Epidemiology and End Results cancer registries. For colon cancer, 1-year RS ranged from 87.8 % [95 % Confidence Interval: 87.5-88.2] in the 50-64-year-olds to 62.3 % [61.3-63.3] in 85-99-year-olds and for rectal cancer ranged from 92.3 % [91.8-92.7] to 65.0 % [62.3-67.5]. With respect to stage, absolute differences in RS between 50-64-year-olds and 75-84-year-olds increased with increasing stage (from 6 [5-7] %-points in localised disease to 27 [25-29] %-points in distant disease) and were the highest for cancers of unknown stage (> 28 %-points). Age-related differences in survival were smallest for persons with tumours in the right-sided colon (8 [7-9] %-points) and largest for tumours of the colon without tumour site further specified (25 [21-29] %-points). With respect to histology, differences ranged from 7.4 % to 10.6 %-points for cancers with one of the three primary histologies (adenocarcinoma, mucinous adenocarcinoma, signet ring cell carcinoma) and were several-fold higher (42 %-points) for those with unknown/other histology (< 6 % of cases). Because age-related differences in survival were observed for all histologies and tumour sites, RS differences are unlikely to be driven by differences in the distribution of these factors by age. Differences in stage distribution by age are likely to contribute toward age-related differences in survival. Within stage groups, age differences in survival could be explained by frailty and/or therapy. Future studies incorporating data on treatment and geriatric conditions including frailty and comorbidity would support further understanding of the age gap in colon and rectal cancer survival.

Immortal-time bias in older vs younger age groups: a simulation study with application to a population-based cohort of patients with colon cancer

BACKGROUND

In observational studies, the risk of immortal-time bias (ITB) increases with the likelihood of early death, itself increasing with age. We investigated how age impacts the magnitude of ITB when estimating the effect of surgery on 1-year overall survival (OS) in patients with Stage IV colon cancer aged 50-74 and 75-84 in England.

METHODS

Using simulations, we compared estimates from a time-fixed exposure model to three statistical methods addressing ITB: time-varying exposure, delayed entry and landmark methods. We then estimated the effect of surgery on OS using a population-based cohort of patients from the CORECT-R resource and conducted the analysis using the emulated target trial framework.

RESULTS

In simulations, the magnitude of ITB was larger among older patients when their probability of early death increased or treatment was delayed. The bias was corrected using the methods addressing ITB. When applied to CORECT-R data, these methods yielded a smaller effect of surgery than the time-fixed exposure approach but effects were similar in both age groups.

CONCLUSION

ITB must be addressed in all longitudinal studies, particularly, when investigating the effect of exposure on an outcome in different groups of people (e.g., age groups) with different distributions of exposure and outcomes.

Age-related differences in cancer relative survival in the United States: A SEER-18 analysis

Cancer survival has improved since the 1990s, but to different extents across age groups, with a disadvantage for older adults. We aimed to quantify age-related differences in relative survival (RS-1-year and 1-year conditioning on surviving 1 year) for 10 common cancer types by stage at diagnosis. We used data from 18 United States Surveillance Epidemiology and End Results cancer registries and included cancers diagnosed in 2012 to 2016 followed until December 31, 2017. We estimated absolute differences in RS between the 50 to 64 age group and the 75 to 84 age group. The smallest differences were observed for prostate and breast cancers (1.8%-points [95% confidence interval (CI): 1.5-2.1] and 1.9%-points [95% CI: 1.5-2.3], respectively). The largest was for ovarian cancer (27%-points, 95% CI: 24-29). For other cancers, differences ranged between 7 (95% CI: 5-9, esophagus) and 18%-points (95% CI: 17-19, pancreas). Except for pancreatic cancer, cancer type and stage combinations with very high (>95%) or very low (<40%) 1-year RS tended to have smaller age-related differences in survival than those with mid-range prognoses. Age-related differences in 1-year survival conditioning on having survived 1-year were small for most cancer and stage combinations. The broad variation in survival differences by age across cancer types and stages, especially in the first year, age-related differences in survival are likely influenced by amenability to treatment. Future work to measure the extent of age-related differences that are avoidable, and identify how to narrow the survival gap, may have most benefit by prioritizing cancers with relatively large age-related differences in survival (eg, stomach, esophagus, liver and pancreas).

Association between metabolic overweight/obesity phenotypes and readmission risk in patients with lung cancer: A retrospective cohort study

BACKGROUND

Increased body mass index (BMI) and metabolic abnormalities are controversial prognostic factors of lung cancer. However, the relationship between metabolic overweight/obesity phenotypes and hospital readmission in patients with lung cancer is rarely reported.

METHODS

We established a retrospective cohort using the United States (US) Nationwide Readmissions Database (NRD). We included adult patients diagnosed with lung cancer from January 1, 2018 to November 30, 2018 and excluded patients combined with other cancers, pregnancy, died during hospitalization, low body weight, and those with missing data. The cohort was observed for hospital readmission until December 31, 2018. We defined and distinguished four metabolic overweight/obesity phenotypes: metabolically healthy with normal weight (MHNW), metabolically unhealthy with normal weight (MUNW), metabolically healthy with overweight or obesity (MHO), and metabolically unhealthy with overweight or obesity (MUO). The relationship between metabolic overweight/obesity phenotypes and 30-day readmission risk was assessed by multivariable Cox regression analysis.

FINDINGS

Of the 115,393 patients included from the NRD 2018 (MHNW [58214, 50.4%], MUNW [44980, 39.0%], MHO [5044, 4.4%], and MUO [7155, 6.2%]), patients with the phenotype MUNW (6531, 14.5%), MHO (771, 15.3%), and MUO (1155, 16.1%) had a higher readmission rate compared to those with MHNW (7901, 13.6%). Compared with patients with the MHNW phenotype, those with the MUNW (hazard ratio [HR], 1.10; 95% CI, 1.06-1.14), MHO (HR, 1.15; 95% CI, 1.07-1.24), and MUO (HR, 1.28; 95% CI, 1.20-1.36) phenotypes had a higher risk of readmission, especially in men, those without surgical intervention, or those aged >60 years. In women, similar results with respect to readmission were observed in people aged >60 years (MUNW [HR, 1.07; 95% CI, 1.01-1.13], MHO [HR, 1.19; 95% CI, 1.06-1.35], and MUO [HR, 1.28; 95% CI, 1.16-1.41]). We also found increased costs for 30-day readmission in patients with MHO (OR, 1.18; 95% CI, 1.07-1.29) and MUO (OR, 1.11; 95% CI, 1.02-1.20).

INTERPRETATION

Increased BMI and metabolic abnormalities are independently associated with higher readmission risks in patients with lung cancer, whereas increased BMI also increases the readmission costs. Follow-up and intervention method targeting increased BMI and metabolic abnormalities should be considered for patients with lung cancer.

FUNDING

The National Key Research and Development Program of China (2017YFC1309800).

Cancer Survival in Adults in Spain: A Population-Based Study of the Spanish Network of Cancer Registries (REDECAN)

Simple Summary

We studied cancer survival and its trends in adult patients in Spain. We included more than 600,000 patients with primary cancer diagnosed during 2002–2013 and followed them up to 2015. The study provides cancer survival estimates up to five years after diagnosis by sex and age for 29 cancer groups. We found survival improvements for most cancer groups from 2002–2007 to 2008–2013, although with differences by age, being greater for patients younger than 75 years than for older patients. The persistent poor prognosis for some cancers emphasizes the need to reinforce actions along the cancer continuum, from primary prevention to early diagnosis, optimal treatment, and supportive care. Further examination of possible sociodemographic inequalities is warranted.

Abstract

The assessment of cancer survival at the population level is essential for monitoring progress in cancer control. We aimed to assess cancer survival and its trends in adults in Spain. Individual records of 601,250 adults with primary cancer diagnosed during 2002–2013 and followed up to 2015 were included from 13 population-based cancer registries. We estimated net survival up to five years after diagnosis and analyzed absolute changes between 2002–2007 and 2008–2013. Estimates were age-standardized. Analyses were performed for 29 cancer groups, by age and sex. Overall, age-standardized five-year net survival was higher in women (61.7%, 95% CI 61.4–62.1%) than in men (55.3%, 95% CI 55.0–55.6%), and ranged by cancer from 7.2% (pancreas) to 89.6% (prostate) in men, and from 10.0% (pancreas) to 93.1% (thyroid) in women in the last period. Survival declined with age, showing different patterns by cancer. Between both periods, age-standardized five-year net survival increased overall by 3.3% (95% CI 3.0–3.7%) in men and 2.5% (95% CI 2.0–3.0%) in women, and for most cancer groups. Improvements were greater in patients younger than 75 years than in older patients. Chronic myeloid leukemia and myeloma showed the largest increases. Among the most common malignancies, the greatest absolute increases in survival were observed for colon (5.0%, 95% CI 4.0–6.0%) and rectal cancers (4.5%, 95% CI 3.2–5.9%). Survival improved even for some cancers with poor prognosis (pancreas, esophagus, lung, liver, and brain cancer). Further investigation of possible sociodemographic inequalities is warranted. This study contributes to the evaluation of cancer control and health services’ effectiveness.

A Prediction Model for Tumor Recurrence in Stage II–III Colorectal Cancer Patients: From a Machine Learning Model to Genomic Profiling

Background: Colorectal cancer (CRC) is one of the most prevalent malignant diseases worldwide. Risk prediction for tumor recurrence is important for making effective treatment decisions and for the survival outcomes of patients with CRC after surgery. Herein, we aimed to explore a prediction algorithm and the risk factors for postoperative tumor recurrence using a machine learning (ML) approach with standardized pathology reports for patients with stage II and III CRC. Methods: Pertinent clinicopathological features were compiled from medical records and standardized pathology reports of patients with stage II and III CRC. Four ML models based on logistic regression (LR), random forest (RF), classification and regression decision trees (CARTs), and support vector machine (SVM) were applied for the development of the prediction algorithm. The area under the curve (AUC) of the ML models was determined in order to compare the prediction accuracy. Genomic studies were performed using a panel-targeted next-generation sequencing approach. Results: A total of 1073 patients who received curative intent surgery at the National Cheng Kung University Hospital between January 2004 and January 2019 were included. Based on conventional statistical methods, chemotherapy (p = 0.003), endophytic tumor configuration (p = 0.008), TNM stage III disease (p < 0.001), pT4 (p < 0.001), pN2 (p < 0.001), increased numbers of lymph node metastases (p < 0.001), higher lymph node ratios (LNR) (p < 0.001), lymphovascular invasion (p < 0.001), perineural invasion (p < 0.001), tumor budding (p = 0.004), and neoadjuvant chemoradiotherapy (p = 0.025) were found to be correlated with the tumor recurrence of patients with stage II–III CRC. While comparing the performance of different ML models for predicting cancer recurrence, the AUCs for LR, RF, CART, and SVM were found to be 0.678, 0.639, 0.593, and 0.581, respectively. The LR model had a better accuracy value of 0.87 and a specificity value of 1 in the testing set. Two prognostic factors, age and LNR, were selected by multivariable analysis and the four ML models. In terms of age, older patients received fewer cycles of chemotherapy and radiotherapy (p < 0.001). Right-sided colon tumors (p = 0.002), larger tumor sizes (p = 0.008) and tumor volumes (p = 0.049), TNM stage II disease (p < 0.001), and advanced pT3–4 stage diseases (p = 0.04) were found to be correlated with the older age of patients. However, pN2 diseases (p = 0.005), lymph node metastasis number (p = 0.001), LNR (p = 0.004), perineural invasion (p = 0.018), and overall survival rate (p < 0.001) were found to be decreased in older patients. Furthermore, PIK3CA and DNMT3A mutations (p = 0.032 and 0.039, respectively) were more frequently found in older patients with stage II–III CRC compared to their younger counterparts. Conclusions: This study demonstrated that ML models have a comparable predictive power for determining cancer recurrence in patients with stage II–III CRC after surgery. Advanced age and high LNR were significant risk factors for cancer recurrence, as determined by ML algorithms and multivariable analyses. Distinctive genomic profiles may contribute to discrete clinical behaviors and survival outcomes between patients of different age groups. Studies incorporating complete molecular and genomic profiles in cancer prediction models are beneficial for patients with stage II–III CRC.

The impact of timely cancer diagnosis on age disparities in colon cancer survival

OBJECTIVE

We described the role of patient-related and clinical factors on age disparities in colon cancer survival among patients aged 50-99 using New Zealand population-based cancer registry data linked to hospitalisation data.

METHOD

We included 21,270 new colon cancer cases diagnosed between 1 January 2006 and 31 July 2017, followed up to end 2019. We modelled the effect of age at diagnosis, sex, ethnicity, deprivation, comorbidity, and emergency presentation on colon cancer survival by stage at diagnosis using flexible excess hazard regression models.

RESULTS

The excess mortality in older patients was minimal for localised cancers, maximal during the first six months for regional cancers, the first eighteen months for distant cancers, and over the three years for missing stages. The age pattern of the excess mortality hazard varied according to sex for distant cancers, emergency presentation for regional and distant cancers, and comorbidity for cancer with missing stages. Ethnicity and deprivation did not influence age disparities in colon cancer survival.

CONCLUSION

Factors reflecting timeliness of cancer diagnosis most affected age-related disparities in colon cancer survival, probably by impacting treatment strategy. Because of the high risk of poor outcomes related to treatment in older patients, efforts made to improve earlier diagnosis in older patients are likely to help reduce age disparities in colon cancer survival in New Zealand.

Age disparities in lung cancer survival in New Zealand: The role of patient and clinical factors

OBJECTIVE

Age is an important prognostic factor for lung cancer. However, no studies have investigated the age difference in lung cancer survival per se. We, therefore, described the role of patient-related and clinical factors on the age pattern in lung cancer excess mortality hazard by stage at diagnosis in New Zealand.

MATERIALS AND METHODS

We extracted 22 487 new lung cancer cases aged 50-99 (median age = 71, 47.1 % females) diagnosed between 1 January 2006 and 31 July 2017 from the New Zealand population-based cancer registry and followed up to December 2019. We modelled the effect of age at diagnosis, sex, ethnicity, deprivation, comorbidity, and emergency presentation on the excess mortality hazard by stage at diagnosis, and we derived corresponding lung cancer net survival.

RESULTS

The age difference in net survival was particularly marked for localised and regional lung cancers, with a sharp decline in survival from the age of 70. No identified factors influenced age disparities in patients with localised cancer. However, for other stages, females had a greater difference in survival between middle-age and older-age than males. Comorbidity and emergency presentation played a minor role. Ethnicity and deprivation did not influence age disparities in lung cancer survival.

CONCLUSION

Sex and stage at diagnosis were the most important factors of age disparities in lung cancer survival in New Zealand.