Second solid cancers after radiotherapy for breast cancer in SEER cancer registries

Background:

Radiotherapy for breast cancer reduces disease recurrence and breast cancer mortality. However, it has also been associated with increased second cancer risks in exposed sites.

Methods:

We evaluated long-term second cancer risks among 182 057 5-year survivors of locoregional invasive breast cancer diagnosed between 1973 and 2000 and reported to US NCI-SEER Program cancer registries. Multivariate Poisson regression was used to estimate the relative risk (RR) and excess cases of second cancer in women who had surgery and radiotherapy, compared with those who had surgery alone. Second cancer sites were grouped according to doses received from typical tangential breast fields.

Results:

By the end of 2005 (median follow-up=13.0 years), 15 498 second solid cancers had occurred, including 6491 contralateral breast cancers. The RRs for radiotherapy were 1.45 (95% confidence interval (CI)=1.33–1.58) for high-dose second cancer sites (1+ Gy: lung, oesophagus, pleura, bone and soft tissue) and 1.09 (1.04–1.15) for contralateral breast cancer (≈1 Gy). These risks decreased with increasing age and year of treatment. There was no evidence of elevated risks for sites receiving medium (0.5–0.99 Gy, RR=0.89 (0.74–1.06)) or low doses (<0.5 Gy, RR=1.01 (0.95–1.07)). The estimated excess cases of cancer in women treated with radiotherapy were as follows: 176 (95% CI=69–284) contralateral breast cancers or 5% (2–8%) of the total in all 1+year survivors, and 292 (222–362) other solid cancers or 6% (4–7%) of the total.

Conclusions:

Most second solid cancers in breast cancer survivors are not related to radiotherapy.     

The risk of cancer in primary care patients with hypercalcaemia: a cohort study using electronic records

Background:

The risk of cancer with hypercalcaemia in primary care is unknown.

Methods:

This was a cohort study using calcium results in patients aged ⩾40 years in a primary care electronic data set. Diagnoses of cancer in the following year were identified.

Results:

Participants (54 267) had calcium results: 1674 (3%) were ⩾2.6 mmol l⁻¹. Hypercalcaemia was strongly associated with cancer, especially in males: OR 2.92, 95% CI 2.17–3.93, P=<0.001; positive predictive value (PPV) 11.5% females: OR 1.86, 95% CI 1.39–2.50, P<0.001: PPV 4.1%.

Conclusions:

Hypercalcaemia is strongly associated with cancer in primary care, with men at most risk, despite hypercalcaemia being more common in women.     

Physical function as a prognostic biomarker among cancer survivors

Background:

We tested the hypothesis that objectively measured physical function predicts mortality among cancer survivors.

Methods:

We assessed objectively measured physical function including the short physical performance battery (SPPB) and fast walk speed in older adult cancer survivors.

Results:

Among 413 cancer survivors, 315 (76%) died during a median follow-up of 11.0 years. In multivariable-adjusted analyses, each 1-unit increase in the SPPB score and 0.1 m s⁻¹ increase in fast walk speed predicted a 12% reduction in mortality (hazard ratio (HR): 0.88 (95% confidence interval (CI): 0.82–0.94); P<0.001, and HR: 0.88 (95% CI: 0.82–0.96); P=0.003, respectively).

Conclusions:

Objectively measured physical function may predict mortality among cancer survivors.     

Alcohol intake and risk of colorectal cancer: Results from the UK Dietary Cohort Consortium

Background:

Epidemiological studies have suggested that excessive alcohol intake increases colorectal cancer (CRC) risk. However, findings regarding tumour subsites and sex differences have been inconsistent.

Methods:

We investigated the prospective associations between alcohol intake on overall and site- and sex-specific CRC risk. Analyses were conducted on 579 CRC cases and 1996 matched controls nested within the UK Dietary Cohort Consortium using standardised data obtained from food diaries as a main nutritional method and repeated using data from food frequency questionnaire (FFQ).

Results:

Compared with individuals in the lightest category of drinkers (>0–<5 g per day), the multivariable odds ratios of CRC were 1.16 (95% confidence interval (95% CI): 0.88, 1.53) for non-drinkers, 0.91 (95% CI: 0.67, 1.24) for drinkers with 5–<15 g per day, 0.90 (95% CI: 0.65, 1.25) for drinkers with 15–<30 g per day, 1.02 (95% CI: 0.66, 1.58) for drinkers with 30–<45 g per day and 1.19 (95% CI: 0.75, 1.91) for drinkers with ⩾45 g per day. No clear associations were observed between site-specific CRC risk and alcohol intake in either sex. Analyses using FFQ showed similar results.

Conclusion:

We found no significantly increased risk of CRC up to 30 g per day of alcohol intake within the UK Dietary Cohort Consortium.     

Alcohol intake and endometrial cancer risk: a meta-analysis of prospective studies

Background:

Studies on alcohol intake in relation to endometrial cancer risk have produced inconsistent results.

Methods:

For a meta-analysis, we identified cohort studies of alcohol and endometrial cancer by a literature search of Pub-Med and Embase up to 1 March 2010 and by searching the reference lists of relevant articles.

Results:

Seven cohort studies, including 1 511 661 participants and 6086 endometrial cancer cases, were included in the dose–response random-effect meta-regression model. Compared with non-drinkers, women drinking less than 1 drink of alcohol (13 g of ethanol) per day had a lower risk for endometrial cancer; this risk was lower by 4% (95% confidence interval (95% CI): 0.93–1.00) for consumption up to 0.5 drink per day and by 7% (95% CI: 0.85–1.02) for consumption up to 1 drink. However, we found evidence of an increased risk for endometrial cancer for intakes higher than two alcoholic drinks per day: compared with non-drinkers, the risk was higher by 14% (95% CI: 0.95–1.36) for 2–2.5 drinks per day and by 25% (95% CI: 0.98–1.58) for >2.5 drinks per day.

Conclusion:

Our meta-analysis indicates a possible J-shaped relationship between alcohol intake and endometrial cancer risk.     

A retrospective analysis of clinical outcome of patients with chemo-refractory metastatic breast cancer treated in a single institution phase I unit

Background and methods:

Novel approaches to treat chemo-refractory metastatic breast cancer (MBC) are currently under investigation. This retrospective series reviews the outcome of 70 MBC patients who have participated in 30 phase I trials at the Royal Marsden Hospital from 2002 to 2009.

Results:

The median treatment lines before phase I trial entry for MBC was 5 (range: 1–12 lines). The overall response rate was 11.4% (95% CI: 4.0–18.9%) and the clinical benefit rate at 4 months was 20% (95% CI: 10.6–29.3). The median time to progression was 7.0 weeks (95% CI: 6.4–7.5) and median overall survival was 8.7 months (95% CI: 7.6–9.8) from start of first phase I treatment. No patients discontinued trial because of treatment-related toxicities. Abnormal lactate dehydrogenase, serum albumin <35 mg  per 100 ml, ⩾5 previous treatment lines, liver metastases and Eastern Cooperative Group performance status ⩾2 at study entry were significantly associated with poor overall survival in multivariate analysis.

Conclusion:

This retrospective analysis provides evidence that patients with MBC tolerate phase I clinical trials and a significant proportion of patients with chemo-refractory disease, particularly those with triple-negative or Her2-positive breast cancer, may benefit from treatment.     

Employment and social benefits up to 10 years after breast cancer diagnosis: a population-based study

Background:

Little is known about employment outcomes after breast cancer (BC) beyond the first years after treatment.

Methods:

Employment outcomes were compared with a general population comparison group (N=91 593) up to 10 years after BC for 26 120 patients, diagnosed before age 55 between 2000–2005, with income and social benefits data from Statistics Netherlands. Treatment effects were studied in 14 916 patients, with information on BC recurrences and new cancer events.

Results:

BC survivors experienced higher risk of losing paid employment (Hazard Ratio (HR): 1.6, 95% Confidence Interval (95% CI) 1.4–1.8) or any work-related event up to 5–7 years (HR 1.5, 95% CI 1.3–1.6) and of receiving disability benefits up to 10 years after diagnosis (HR 2.0, 95% CI 1.6–2.5), with higher risks for younger patients. Axillary lymph node dissection increased risk of disability benefits (HR 1.5, 95% CI 1.4–1.7) or losing paid employment (HR 1.3, 95% CI 1.2–1.5) during the first 5 years of follow-up. Risk of disability benefits was increased among patients receiving mastectomy and radiotherapy (HR 1.2; 95% CI 1.1–1.3) and after chemotherapy (HR 1.7; 95% CI 1.5–1.9) during the first 5 years after diagnosis.

Conclusions:

BC treatment at least partly explains the increased risk of adverse employment outcomes up to 10 years after BC.     

Alcohol consumption and risk of renal cell cancer: the NIH-AARP diet and health study

Background:

The effect of moderate to heavy drinking (>15 g per day) on renal cell cancer (RCC) risk is unclear.

Method:

The relationship between alcohol consumption and RCC was examined in the NIH-AARP Diet and Health Study (n=49 2187, 1814 cases).

Results:

Compared with >0 to <5 g per day of alcohol consumption, the multivariate relative risk (95% confidence intervals) for 15 to <30 and ⩾30 g per day was, 0.75 (0.63–0.90) and 0.71 (0.59–0.85), respectively, in men and 0.67 (0.42–1.07) and 0.43 (0.22–0.84), respectively, in women.

Conclusion:

Alcohol consumption was inversely associated with RCC in a dose–response manner. The inverse association may be extended to ⩾30 g per day of alcohol intake.     

A urine-based methylation signature for risk stratification within low-risk prostate cancer

Background:

Prostate cancer overdiagnosis and overtreatment represents a major problem. Many men with low-grade disease on biopsy are undergraded and they harbour high-grade disease at prostatectomy with no reliable way to identify these men. We used a novel urine-based 2-gene methylation test to identify prostate cancers with aggressive features.

Methods:

Following a proof of concept study in 100 post-radical prostatectomy tissue samples, urine samples were tested from 665 men at multiple U.S. centers undergoing prostate needle biopsy for elevated prostate-specific antigen (2–10 ng ml⁻¹). A prediction model was then developed from a combination of clinical factors and the urine-based markers. It was then prospectively tested for accurate prediction of adverse disease (surgical Gleason score ⩾7 and/or a pathological stage ⩾T3a) using urine from a separate cohort of 96 men before radical prostatectomy.

Results:

Among pre-prostatectomy men with a biopsy Gleason score <7, 41% had adverse disease of which 100% were correctly identified by the test with a negative predictive value of 100% (95% confidence interval, 86–100%).

Conclusions:

This urine-based test accurately identifies men with clinical low-risk disease who do not have adverse pathology in their prostates and would be excellent candidates for active surveillance.     

Background risk of breast cancer influences the association between alcohol consumption and mammographic density

Background:

Alcohol consumption has been suggested to increase risk of breast cancer through a mechanism that also increases mammographic density. Whether the association between alcohol consumption and mammographic density is modified by background breast cancer risk has, however, not been studied.

Methods:

We conducted a population-based cross-sectional study of 53 060 Swedish women aged 40–74 years. Alcohol consumption was assessed using a web-based self-administered questionnaire. Mammographic density was measured using the fully-automated volumetric Volpara method. The Tyrer–Cuzick prediction model was used to estimate risk of developing breast cancer in the next 10 years. Linear regression models were used to evaluate the association between alcohol consumption and volumetric mammographic density and the potential influence of Tyrer–Cuzick breast cancer risk.

Results:

Overall, increasing alcohol consumption was associated with higher absolute dense volume (cm³) and per cent dense volume (%). The association between alcohol consumption and absolute dense volume was most pronounced among women with the highest (⩾5%) Tyrer–Cuzick 10-year risk. Among high-risk women, women consuming 5.0–9.9, 10.0–19.9, 20.0–29.9, and 30.0–40.0 g of alcohol per day had 2.6 cm³ (95% confidence interval (CI), 0.2–4.9), 2.9 cm³ (95% CI, −0.6 to 6.3), 4.6 cm³ (95% CI, 1.5–7.7), and 10.8 cm³ (95% CI, 4.8–17.0) higher absolute dense volume, respectively, as compared with women abstaining from alcohol. A trend of increasing alcohol consumption and higher absolute dense volume was seen in women at low (⩽3%) risk, but not in women at moderate (3.0–4.9%) risk.

Conclusion:

Alcohol consumption may increase breast cancer risk through increasing mammographic density, particularly in women at high background risk of breast cancer.     

Randomised pilot study of dose escalation using conformal radiotherapy in prostate cancer: long-term follow-up

Background:

Radical three-dimensional conformal radiotherapy (CFRT) with initial androgen suppression (AS) is a standard management for localised prostate cancer (PC). This pilot study evaluated the role of dose escalation and appropriate target volume margin. Here, we report long-term follow-up.

Methods:

Eligible patients had T1b-T3b N0 M0 PC. After neoadjuvant AS, they were randomised to CFRT, giving (a) 64 Gy with either a 1.0- or 1.5-cm margin and (b) ±10 Gy boost to the prostate alone.

Results:

One hundred and twenty-six men were randomised and treated. Median follow-up was 13.7 years. The median age was 66.6 years at randomisation. Median presenting prostate-specific antigen (PSA) was 14 ng ml⁻¹. Sixty-four out of 126 patients developed PSA failure. Forty-nine out of 126 patients restarted AS, 34 out of 126 developed metastases and 28 out of 126 developed castrate-resistant prostate cancer (CRPC). Fifty-one out of 126 patients died; 19 out of 51 died of PC. Median overall survival (OS) was 14.4 years. Although escalated dose results were favourable, no statistically significant differences were seen between the randomised groups; PSA control (hazard ratio (HR): 0.77 (95% confidence interval (CI): 0.47–1.26)), development of CRPC (HR: 0.81 (95% CI: 0.40–1.65)), PC-specific survival (HR: 0.59 (95% CI:0.23–1.49)) and OS (HR: 0.81 (95% CI: 0.47–1.40)). There was no evidence of a difference in PSA control according to margin size (HR: 1.01 (95% CI: 0.61–1.66)).

Interpretation:

Long-term follow-up of this small pilot study is compatible with a benefit from dose escalation, but confirmation from larger trials is required. There was no obvious detriment using the smaller radiotherapy margin.     

A phase II study of weekly neoadjuvant chemotherapy followed by radical chemoradiation for locally advanced cervical cancer

Background:

We investigated the feasibility of dose-dense neoadjuvant chemotherapy (NACT) with paclitaxel and carboplatin before radical chemoradiation (CRT) and assessed the response rate to such a regimen.

Methods:

CxII is a single-arm phase II trial of 46 patients, with locally advanced cervical cancer (stage Ib2-IVa). Patients received dose-dense carboplatin (AUC2) and paclitaxel (80 mg m⁻²) weekly for six cycles followed by CRT (40 mg m⁻² of weekly cisplatin, 50.4 Gy, 28 fractions plus brachytherapy). The primary end point was response rate 12 weeks post-CRT.

Results:

Baseline characteristics were: median age at diagnosis 43 years; 72% squamous, 22% adenocarcinoma and 7% adenosquamous histologies; FIGO stage IB2 (11%), II (50%), III (33%), IV (7%). Complete or partial response rate was 70% (95% CI: 54–82) post-NACT and 85% (95% CI: 71–94) post-CRT. The median follow-up was 39.1 months. Overall and progression-free survivals at 3 years were 67% (95% CI: 51–79) and 68% (95% CI: 51–79), respectively. Grade 3/4 toxicities were 20% during NACT (11% haematological, 9% non-haematological) and 52% during CRT (haematological: 41%, non-haematological: 22%).

Conclusion:

A good response rate is achieved by dose-dense weekly NACT with carboplatin and paclitaxel followed by radical CRT. This treatment regimen is feasible as evidenced by the acceptable toxicity of NACT and by the high compliance to radiotherapy (98%).     

New-onset type 2 diabetes,elevated HbA1c,anti-diabetic medications,and risk of pancreatic cancer

Background:

Associations between type 2 diabetes, anti-diabetic medications and pancreatic cancer are controversial. This study aims to clarify such associations with new-onset type 2 diabetes and repeated measurements of glycated haemoglobin (HbA1c) levels.

Methods:

A nested case–control study was initiated from the Health Improvement Network (THIN) in UK from 1996 to 2010. Information of pancreatic cancer cases was retrieved electronically from the medical records and manually validated. Control subjects were randomly selected and frequency-matched to the cases on sex, age, and calendar years. Multivariable unconditional logistic regression was performed to estimate odds ratios (OR) and 95% confidence intervals (CI), and adjusted for potential confounders.

Results:

Among 1 574 768 person-years of follow-up, 529 pancreatic cancer cases and 5000 controls were identified. Type 2 diabetes, or changed HbA1c levels (rather than HbA1c levels at diabetes diagnosis) in diabetes patients (⩾4 mmol mol⁻¹ compared with <0 mmol mol⁻¹) were followed by an increased OR of pancreatic cancer (OR, 2.16, 95% CI 1.72–2.72 and OR, 5.06, 95% CI 1.52–16.87, respectively). Among the anti-diabetic medications in diabetes patients, the OR for insulin users was 25.57 (95% CI 11.55–56.60), sulphonylureas 2.22 (95% CI 1.13, 4.40), and metformin users 1.46 (95% CI 0.85–2.52), compared with no use of any anti-diabetic medications.

Conclusions:

New-onset type 2 diabetes and, particularly, diabetes with rising HbA1c seem to be independent risk factors for pancreatic cancer. The relation between different anti-diabetic medications and pancreatic cancer seems to vary in strength, with the highest risk among users of insulin.     

Tubal ligation in relation to menopausal symptoms and breast cancer risk

Background:

Local inflammation after tubal ligation may affect ovarian function and breast cancer risk.

Methods:

We analysed tubal ligation, menopausal characteristics, and breast cancer risk in the Sister Study cohort (N=50 884 women).

Results:

Tubal ligation was associated with hot flashes (hazard ratio (HR) 1.09; 95% confidence interval (CI): 1.06–1.12) but not menopausal age (HR 0.99; 95% CI: 0.96–1.02). Tubal ligation did not have an impact on breast cancer overall (HR 0.95; 95% CI: 0.85–1.06), but had a suggested inverse relation with oestrogen receptor+/progesterone receptor+ invasive tumours (HR 0.84; 95% CI: 0.70–1.01), possibly because of subsequent hysterectomy/bilateral oophorectomy.

Conclusion:

Tubal ligation does not influence overall breast cancer risk.     

Quantifying the natural history of breast cancer

Background:

Natural history models of breast cancer progression provide an opportunity to evaluate and identify optimal screening scenarios. This paper describes a detailed Markov model characterising breast cancer tumour progression.

Methods:

Breast cancer is modelled by a 13-state continuous-time Markov model. The model differentiates between indolent and aggressive ductal carcinomas in situ tumours, and aggressive tumours of different sizes. We compared such aggressive cancers, that is, which are non-indolent, to those which are non-growing and regressing. Model input parameters and structure were informed by the 1978–1984 Ostergotland county breast screening randomised controlled trial. Overlaid on the natural history model is the effect of screening on diagnosis. Parameters were estimated using Bayesian methods. Markov chain Monte Carlo integration was used to sample the resulting posterior distribution.

Results:

The breast cancer incidence rate in the Ostergotland population was 21 (95% CI: 17–25) per 10 000 woman-years. Accounting for length-biased sampling, an estimated 91% (95% CI: 85–97%) of breast cancers were aggressive. Larger tumours, 21–50 mm, had an average sojourn of 6 years (95% CI: 3–16 years), whereas aggressive ductal carcinomas in situ took around half a month (95% CI: 0–1 month) to progress to the invasive ⩽10 mm state.

Conclusion:

These tumour progression rate estimates may facilitate future work analysing cost-effectiveness and quality-adjusted life years for various screening strategies.     

Insulin-like growth factors and risk of kidney cancer in men

Background:

Insulin-like growth factor-I (IGF-I) has been shown to increase kidney growth, glomerular filtration rate, and renal function.

Methods:

In the prospective Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) study of 29 133 Finnish male smokers aged 50–69 years, serum concentrations of IGF were measured in samples collected in 1985–1988. A total of 100 men with kidney cancer diagnosed ⩾5 years after blood collection through 1997 were compared with a subcohort of 400 men; logistic regression models were used to estimate the risk of developing kidney cancer.

Results:

Men with IGF-I levels >113 ng ml⁻¹ were 59% less likely to develop kidney cancer than men with levels ⩽113 ng ml⁻¹ (odds ratio=0.41; 95% confidence interval=0.23–0.75). The IGF binding protein-3 (IGFBP-3) levels did not alter the association. No association was observed between IGFBP-3, or molar ratio of IGF-I/IGFBP-3, and kidney cancer.

Conclusions:

Low serum IGF-I levels in this cohort of older middle-aged male smokers are associated with increased kidney cancer risk, independent of IGFBP-3.     

Supplemental folic acid in pregnancy and childhood cancer risk

Background:

We investigated the association between supplemental folic acid in pregnancy and childhood cancer in a nation-wide study of 687 406 live births in Norway, 1999–2010, and 799 children diagnosed later with cancer.

Methods:

Adjusted hazard ratios (HRs) compared cancer risk in children by approximated periconceptional folic acid levels (folic acid tablets and multivitamins (0.6 mg), only folic acid (0.4 mg), only multivitamins (0.2 mg)) and cancer risk in unexposed.

Results:

Any folic acid levels were not associated with leukemia (e.g., high-level folic acid HR 1.25; 95% CI 0.89–1.76, P_Trend 0.20), lymphoma (HR 0.96; 95% CI 0.42–2.21, P_Trend 0.51), central nervous system tumours (HR 0.68; 95% CI 0.42–1.10, P_Trend 0.32), neuroblastoma (HR 1.05; 95% CI 0.53–2.06, P_Trend 0.85), Wilms'' tumour (HR 1.16; 95% CI 0.52–2.58, P_Trend 0.76), or soft-tissue tumours (HR 0.77; 95% CI 0.34–1.75, P_Trend 0.90).

Conclusions:

Folic acid supplementation was not associated with risk of major childhood cancers.     

Diabetes mellitus and the risk of bladder cancer: an Italian case–control study

Background:

Diabetes mellitus has been associated with an increased risk of bladder cancer, although the evidence is still open to discussion.

Methods:

We examined this association using data from a multicentre Italian case–control study, conducted between 2003 and 2014 on 690 bladder cancer cases and 665 frequency-matched hospital controls. Odds ratios (ORs) for diabetes were estimated by unconditional multiple logistic regression models, after allowance for major known risk factors for bladder cancer.

Results:

One hundred and twelve (16.2%) cases and 57 (8.6%) controls reported a diagnosis of diabetes mellitus, corresponding to a multivariate OR of 2.09 (95% confidence interval (CI): 1.46–3.01). Bladder cancer risk increased with duration of diabetes (OR 1.92 for 1–<5 years, 1.63 for 5–<10 years, 2.39 for 10–<15 years, and 2.58 for ⩾15 years). The increased risk of bladder cancer was consistent in strata of age and education, whereas it was somewhat lower (although not significantly) in women (OR 1.18), in never (OR 1.31) and current (OR 1.42) smokers, and in subjects with a body mass index <25 kg m⁻² (OR 1.48).

Conclusion:

The present study provides further support of a role of diabetes in bladder cancer aetiology, although some residual confounding by tobacco, body mass index, or other unmeasured covariates may partly explain the association observed.     

Lung cancer mortality in a cohort of UK cotton workers: an extended follow-up

Background:

A recent systematic review and meta-analysis suggested that occupational exposure to endotoxins protects against lung cancer. To explore this hypothesis further, the follow-up of mortality of a cohort of 3551 workers, who were employed in the British cotton industry during 1966–1971, was extended by 23 years.

Methods:

Subjects had originally been recruited to a survey of respiratory disease, which collected information about occupation and smoking habits. Cumulative exposures to endotoxins were estimated from data on endotoxin levels by work areas in cotton mills. Risks of lung cancer were estimated using survival modelling.

Results:

During follow-up, 2018 deaths were recorded before the age of 90 years, including 128 deaths from lung cancer. After adjustment for smoking, hazard ratios (95% confidence intervals) for cumulative endotoxin exposures of ⩽30 000, >30 000 and ⩽200 000, >200 000 and ⩽400 000, >400 000 and ⩽600 000 and >600 000 endotoxin units (EU) m⁻³ years were 1, 0.8 (0.5–1.6), 0.7 (0.4–1.3), 0.6 (0.3–1.0) and 0.5 (0.3–0.9), respectively (P for trend=0.005).

Conclusion:

Our findings strengthen the evidence that occupational exposure to endotoxins protects against lung cancer, and suggest that the effect depends on cumulative dose and persists after exposure ceases.     

Who are the cancer survivors? A nationwide study in Denmark, 1943–2010

Background:

No nationwide studies on social position and prevalence of comorbidity among cancer survivors exist.

Methods:

We performed a nationwide prevalence study defining persons diagnosed with cancer 1943–2010 and alive on the census date 1 January 2011 as cancer survivors. Comorbidity was compared by social position with the non-cancer population.

Results:

Cancer survivors composed 4% of the Danish population. Somatic comorbidity was more likely among survivors (OR 1.59, 95% CI 1.57–1.60) and associated with higher age, male sex, short education, and living alone among survivors.

Conclusions:

Among cancer survivors, comorbidity is common and highly associated with social position.