Myocardial infarction in diffuse large B-cell lymphoma patients - a population-based matched cohort study

BACKGROUND

The outcome for diffuse large B-cell lymphoma (DLBCL) patients has improved with the immunochemotherapy combination R-CHOP. An increased rate of heart failure is well documented following this treatment, whereas incidence and outcome of other cardiac complications, for example myocardial infarction, are less well known.

METHOD

We identified 3548 curatively treated DLBCL patients in Sweden diagnosed between 2007 and 2014, and 35474 matched lymphoma-free general population comparators. The incidence, characteristics and outcome of acute myocardial infarctions (AMIs) were assessed using population-based registers up to 11 years after diagnosis. The rate of AMI was estimated using flexible parametric models.

RESULTS

Overall, a 33% excess rate of AMI was observed among DLBCL patients compared with the general population (HR: 1.33, 95% CI: 1.14-1.55). The excess rate was highest during the first year after diagnosis and diminished after 2 years. High age, male sex and comorbidity were the strongest risk factors for AMI. Older patients (>70 years) with mild comorbidities (i.e. hypertension or diabetes) had a 61% higher AMI rate than comparators (HR: 1.61, 95% CI: 1.10-2.35), whereas the corresponding excess rate was 28% for patients with severe comorbidities (HR: 1.28, 95% CI: 1.01-1.64). Among younger patients (≤70), a short-term excess rate of AMI was limited to those with severe comorbidities. There was no difference in AMI characteristics, pharmacological treatment or 30-day survival among patients and comparators.

CONCLUSION

DLBCL patients have an increased risk of AMI, especially during the first 2 years, which calls for improved cardiac monitoring guided by age and comorbidities. Importantly, DLBCL was not associated with differential AMI management or survival.

Cancer survival statistics for patients and healthcare professionals - a tutorial of real-world data analysis

Monitoring survival of cancer patients using data collected by population-based cancer registries is an important component of cancer control. In this setting, patient survival is often summarized using net survival, that is survival from cancer if there were no other possible causes of death. Although net survival is the gold standard for comparing survival between groups or over time, it is less relevant for understanding the anticipated real-world prognosis of patients. In this review, we explain statistical concepts targeted towards patients, clinicians and healthcare professionals that summarize cancer patient survival under the assumption that other causes of death exist. Specifically, we explain the appropriate use, interpretation and assumptions behind statistical methods for competing risks, loss in life expectancy due to cancer and conditional survival. These concepts are relevant when producing statistics for risk communication between physicians and patients, planning for use of healthcare resources, or other applications when consideration of both cancer outcomes and the competing risks of death is required. To reinforce the concepts, we use Swedish population-based data of patients diagnosed with cancer of the breast, prostate, colon and chronic myeloid leukaemia. We conclude that when choosing between summary measures of survival it is critical to characterize the purpose of the study and to determine the nature of the hypothesis under investigation. The choice of terminology and style of reporting should be carefully adapted to the target audience and may range from summaries for specialist readers of scientific publications to interactive online tools aimed towards lay persons.

Family history of colorectal cancer and survival: a Swedish population-based study

OBJECTIVES

A family history of colorectal cancer (CRC) is an established risk factor for developing CRC, whilst the impact of family history on prognosis is unclear. The present study assessed the association between family history and prognosis and, based on current evidence, explored whether this association was modified by age at diagnosis.

METHODS

Using data from the Swedish Colorectal Cancer Registry (SCRCR) linked with the Multigeneration Register and the National Cancer Register, we identified 31 801 patients with a CRC diagnosed between 2007 and 2016. The SCRCR is a clinically rich database which includes information on the cancer stage, grade, location, treatment, complications and postoperative follow-up.

RESULTS

We estimated excess mortality rate ratios (EMRR) for relative survival and hazard ratios (HR) for disease-free survival with 95% confidence intervals (CIs) using flexible parametric models. We found no association between family history and relative survival (EMRR = 0.96, 95% CIs: 0.89-1.03, P = 0.21) or disease-free survival (HR = 0.98, 95% CIs: 0.91-1.06, P = 0.64). However, age was found to modify the impact of family history on prognosis. Young patients (<50 at diagnosis) with a positive family history had less advanced (i.e. stages I and II) cancers than those with no family history (OR = 0.71, 95% CI: 0.56-0.89, P = 0.004) and lower excess mortality even after adjusting for cancer stage (EMMR = 0.63, 95% CIs: 0.47-0.84, P = 0.002).

CONCLUSIONS

Our results suggest that young individuals with a family history of CRC may have greater health awareness, attend opportunistic screening and adopt lifestyle changes, leading to earlier diagnosis and better prognosis.

Impact of comorbidity on disease characteristics, treatment intent and outcome in diffuse large B-cell lymphoma: a Swedish lymphoma register study

BACKGROUND

Comorbidity impacts overall survival amongst patients with diffuse large B-cell lymphoma (DLBCL). However, associations of comorbidity with lymphoma characteristics, treatment selection and lymphoma-specific mortality are less well known.

OBJECTIVE

To examine the impact of comorbidity on DLBCL characteristics, treatment intent and cause of death.

METHODS

We identified 3905 adult patients diagnosed with DLBCL 2007-2013 through the Swedish Lymphoma Register. We assessed comorbid disease history according to the Charlson comorbidity index (CCI). Comorbidity data and causes of death were collected through register linkage. Associations were estimated using multinomial regression and flexible parametric survival models.

RESULTS

Overall, 45% of the patients (n = 1737) had a history of at least one comorbidity at DLBCL diagnosis (cardiovascular disease, diabetes and solid cancer were most frequent), and 997 (26%) had a CCI score of ≥2. The relative probability of presenting with poor performance status (PS > 2) was higher amongst comorbid patients [Relative Risk Ratio (RRR)_PS>2 : 2.02, 95% CI: 1.63-2.51]. Comorbid patients had a substantially lower relative probability of receiving curative treatment (RRR: 0.48, 95% CI: 0.38-0.61). Amongst all patients, CCI ≥ 1 was associated with a significantly increased risk of all-cause and lymphoma-specific death after adjustments. Amongst patients selected for curative treatment, comorbidity was associated with an increased risk of all-cause death (HR_CCI>1 : 1.54, 95% CI: 1.32-1.80), but not with lymphoma-specific death (HR_CCI>1 : 1.05, 95% CI: 0.86-1.28).

CONCLUSION

Comorbidity is associated with inferior DLBCL outcome, mainly due to a lower likelihood of receiving treatment with curative intent. Possibly, more comorbid DLBCL patients could be treated with curative intent if comorbid conditions were optimized in parallel.

Abstract P4-11-05: Safety of fertility preservation indicated by a diagnosis of breast cancer: A Swedish registry-matched cohort study

Purpose

The number of women that perform fertility preservation (FP) before initiating chemotherapy for treatment of breast cancer is increasing. Our purpose was to investigate the safety of performance of fertility preservation with and without hormonal stimulation in the incidence rate of breast cancer relapse.

Patients and methods

The study was designed as a matched cohort study. Women who had undergone FP at the Reproductive Medicine clinic of Karolinska University Hospital (N=187), irrespective of whether hormonal stimulation was required or not, were considered exposed. For all exposed women, two age-matched women who had not undergone fertility preservation were identified in the Regional Breast Cancer Registry Stockholm-Gotland and the Swedish National Quality Registry for Breast Cancer (N=319). The proportional hazards assumption was evaluated by applying the Grambsch-Therneau test on the Schoenfeld residuals obtained from each model, respectively. When interpreting the test results, a significance level of 5% was used to determine statistical significance.

Results

In the exposed cohort, a higher proportion of women underwent FP with hormonal stimulation aiming at freezing eggs or embryos (81%, N=142), whereas only 19% underwent freezing of ovarian tissue or attempted egg retrieval without hormonal stimulation (N=35). The mean follow up time was 6.3 years (range: 1.5-17.8 years), and median follow-up: 5.7 years.

There was no evidence of non-proportional hazards with respect to the effects of fertility preservation on the risk of relapse in the whole FP cohort, irrespective if the women underwent hormonal stimulation or not for FP, or of receptor status or tumour size at diagnosis. A stratified Cox regression model that allowed separate baseline hazard functions for each level for the investigation of the effect of number of involved lymph nodes was performed. In this model, the effect of fertility preservation on the risk of relapse was virtually unchanged (IRR: 1.02, 95% CI:0.56-1.84).

Conclusion

Fertility preservation either using hormone stimulation or not is unlikely to cause substantially increase recurrence risk of breast cancer, and irrespective of the receptor status, tumorur size of lymph node compromise. The incidence of breast cancer relapse after hormonal or non-hormonal fertility preservation was not different from that of matched controls from the Regional Breast Cancer Registry in this large cohort study.

Citation Format: Rodriguez-Wallberg KA, Eloranta S, Krawiec K, Lissmats A, Liljegren A. Safety of fertility preservation indicated by a diagnosis of breast cancer: A Swedish registry-matched cohort study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-11-05.

Risk of disability pension in patients following rectal cancer treatment and surgery

BACKGROUND

Aspects of survivorship, such as long-term ability to work, are increasingly relevant owing to the improved survival of patients with rectal cancer. The aim of this study was to assess risk and determinants of disability pension (DP) in this patient group.

METHODS

Using Swedish national clinical and population-based registers, patients with stage I-III rectal cancer aged 18-61 years in 1995-2009 were identified at diagnosis and matched with population comparators. Prospectively registered records of DP during follow-up were retrieved up to 2013. Non-proportional and proportional hazards models were used to estimate the incidence rate ratio (IRR) for DP annually and overall. Potential variations in risk by demographic and clinical factors were calculated, with relapse as a time-varying exposure.

RESULTS

A total of 2815 patients were identified and compared with 13 465 population comparators. During a median follow-up of 6·0 (range 0-10) years, 23·3 per cent of the relapse-free patients and 10·3 per cent of the population comparators received DP (IRR 2·40, 95 per cent c.i. 2·17 to 2·65). An increased annual risk of DP was evident almost every year until the tenth year of follow-up. Abdominoperineal resection was associated with an increased DP risk compared with anterior resection (IRR 1·44, 1·19 to 1·75). Surgical complications (IRR 1·33, 1·10 to 1·62) and reoperation (IRR 1·42, 1·09 to 1·84), but not radiotherapy or chemotherapy, were associated with risk of DP.

CONCLUSION

Relapse-free patients with rectal cancer of working age are at risk of disability pension.

Does socioeconomic status influence the prospect of cure from colon cancer--a population-based study in Sweden 1965-2000

AIM OF STUDY

Differences in the survival of colon cancer patients by socioeconomic status have been demonstrated in several populations, but the underlying reasons for the differences are not well understood. By simultaneously estimating the proportion of patients cured from colon cancer and the survival times of the 'uncured' we hope to increase understanding of how socioeconomic status affects survival following a diagnosis of colon cancer.

METHODS

We conducted a population-based cohort study of 58,873 patients diagnosed with colon cancer in Sweden 1965-2000. Socioeconomic status was classified based on occupation. We fitted mixture cure models and Poisson regression models adjusted for age, sex and calendar period.

RESULTS

We observed higher excess mortality, lower proportion cured and shorter survival times among the uncured in patients from lower socioeconomic groups compared to the highest socioeconomic group. There was no evidence that the gap between the socioeconomic groups reduced over time. Farmers had the lowest odds of cure (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.75-0.95) compared to higher non-manual workers followed by self-employed (0.91, 0.81-1.03), manual workers (0.93, 0.85-1.03) and lower non-manual workers (0.98, 0.89-1.08).

CONCLUSION

Patients from lower socioeconomic groups in Sweden experience worse survival following a diagnosis of colon cancer. Differences exist in both the cure proportion and the survival time of the uncured, suggesting that socioeconomic differences cannot be attributed solely to lead time bias.Although this study has furthered our understanding of socioeconomic differences in survival, more detailed studies are required in order to identify, and subsequently remove, the underlying reasons for the differences.