Effects of smoking and radiotherapy on lung carcinoma in breast carcinoma survivors

Clinical impact of cigarette smoking on the outcomes of allogeneic hematopoietic stem cell transplantation: a multicenter retrospective study

Smoking is associated with a high risk for different diseases including respiratory tract infections in immunocompetent patients. However, data about the effects of cigarette smoking on the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are limited. Therefore, we retrospectively investigated 608 patients aged ≥20 years with hematological disorders who received their first allo-HSCT at our group of hospitals between 2000 and 2015, and evaluated the impact of cigarette smoking before allo-HSCT on clinical outcomes by dividing patients into two groups according to the Brinkman index (BI) (nonsmokers or light smokers [BI: 0-500] and heavy smokers [BI: ≥ 500]). Multivariate analyses showed that heavy smoking was associated with a high 5-year cumulative incidence of chronic graft-versus-host disease (cGVHD) (hazard ratio [HR]: 1.73, 95% confidence interval [CI]: 1.15-2.61, p < 0.01). The 5-year overall survival (HR: 1.16, 95% CI: 0.86-1.58, p = 0.33) and disease-free survival (HR: 1.12, 95% CI: 0.83-1.52, p = 0.45) were similar between the two groups. Hence, cigarette smoking is correlated with cGVHD, although prospective studies must be conducted to further verify this result.

Primary Lung Cancer After Treatment for Breast Cancer

Breast cancer is the most common malignancy in women and the second most common cause of cancer-related death. Due to advances in the diagnosis and treatment technologies for breast cancer, patients with breast cancer are living longer than before, resulting in an increased risk of developing subsequent malignancies, among which lung cancer is the most common. This review presents the current evidence about the risk, influencing factors and prognostic factors of developing primary lung cancer after treatment for breast cancer. The aim is to help clinicians improve their understanding, diagnosis and treatment of lung cancer after breast cancer.

Mammary Chain Irradiation in Left-Sided Breast Cancer: Can We Reduce the Risk of Secondary Cancer and Ischaemic Heart Disease with Modern Intensity-Modulated Radiotherapy Techniques?

Introduction

The aim of the present study was to estimate the impact of the addition of internal mammary chain (IMC) irradiation in node-positive left-sided breast cancer (BC) patients undergoing regional nodal irradiation (RNI) and comparatively evaluate excess relative and absolute risks of radiation-induced lung cancer/BC and ischaemic heart disease for intensity-modulated radiotherapy (IMRT) versus 3D conformal radiotherapy (3D-CRT).

Methods

Four treatment plans were created (3D-CRT and IMRT -/+ IMC) for each of the 10 evaluated patients, and estimates of excess relative risk (ERR) and 10-year excess absolute risk (EAR) were calculated for radiation-induced lung cancer/BC and coronary events using linear, linear-exponential and plateau models.

Results

The addition of IMC irradiation to RNI significantly increased the dose exposure of the heart, lung and contralateral breast using both techniques, increasing ERR for secondary lung cancer (58 vs. 44%, p = 0.002), contralateral BC (49 vs. 31%, p = 0.002) and ischaemic heart disease (41 vs. 27%, p = 0.002, IMRT plans). IMRT significantly reduced the mean cardiac dose and mean lung dose as compared to 3D-CRT, decreasing ERR for major coronary events (64% 3D-CRT vs. 41% IMRT, p = 0.002) and ERR for secondary lung cancer (75 vs. 58%, p = 0.004) in IMC irradiation, without a significant impact on secondary contralateral BC risks.

Conclusion

Although IMC irradiation has been shown to increase survival rates in node-positive BC patients, it increased dose exposure of organs at risk in left-sided BC, resulting in significantly increased risks for secondary lung cancer/contralateral BC and ischaemic heart disease. In this setting, the adoption of IMRT seems advantageous when compared to 3D-CRT.

Estimating long-term health risks after breast cancer radiotherapy: merging evidence from low and high doses

In breast cancer radiotherapy, substantial radiation exposure of organs other than the treated breast cannot be avoided, potentially inducing second primary cancer or heart disease. While distant organs and large parts of nearby ones receive doses in the mGy-Gy range, small parts of the heart, lung and bone marrow often receive doses as high as 50 Gy. Contemporary treatment planning allows for considerable flexibility in the distribution of this exposure. To optimise treatment with regards to long-term health risks, evidence-based risk estimates are required for the entire broad range of exposures. Here, we thus propose an approach that combines data from medical and epidemiological studies with different exposure conditions. Approximating cancer induction as a local process, we estimate organ cancer risks by integrating organ-specific dose-response relationships over the organ dose distributions. For highly exposed organ parts, specific high-dose risk models based on studies with medical exposure are applied. For organs or their parts receiving relatively low doses, established dose-response models based on radiation-epidemiological data are used. Joining the models in the intermediate dose range leads to a combined, in general non-linear, dose response supported by data over the whole relevant dose range. For heart diseases, a linear model consistent with high- and low-dose studies is presented. The resulting estimates of long-term health risks are largely compatible with rate ratios observed in randomised breast cancer radiotherapy trials. The risk models have been implemented in a software tool PASSOS that estimates long-term risks for individual breast cancer patients.

Risk and Influencing Factors for Subsequent Primary Lung Cancer After Treatment of Breast Cancer: A Systematic Review and Two Meta-Analyses Based on Four Million Cases

INTRODUCTION

To compare the risk of developing lung cancer between patients with breast cancer and the general population and explore the risk factors for the development of primary lung cancer after treatment for breast cancer.

METHODS

The PubMed, EMBASE, and Web of Science databases were searched from the establishment date to October 11, 2020. Two separate meta-analyses were performed: one focused on studies reporting the risk of subsequent lung cancer after breast cancer and one focused on studies exploring the risk factors for subsequent lung cancer in patients with breast cancer. The standardized incidence ratios with 95% confidence intervals were combined to compare the risk of developing lung cancer between patients with breast cancer and the general population. The relative risks (RRs) or ORs with 95% confidence intervals were combined to assess the association of clinicopathological parameters with the risk of developing lung cancer after breast cancer. All statistical analyses were conducted by STATA 12.0.

RESULTS

A total of 15 studies involving 1,161,979 patients were eventually included in the first meta-analysis, and the pooled results indicated that female patients with breast cancer revealed a significantly higher risk of developing subsequent lung cancer (standardized incidence ratio = 1.25, p < 0.001). In addition, a total of 22 articles involving 3,090,620 patients were included in the second meta-analysis. The pooled results indicated that smoking (OR = 9.73, p < 0.001) and radiotherapy (RR = 1.40, p < 0.001) were risk factors for developing subsequent lung cancer in patients with breast cancer, and chemotherapy (RR = 0.69, p = 0.002), positive estrogen receptor status (RR = 0.93, p = 0.014) and positive progesterone receptor status (RR = 0.86, p < 0.001) were protective factors. Meanwhile, subgroup analysis based on the relative position of the breast and lung cancers (ipsilateral versus contralateral) was conducted, which indicated that radiotherapy only increased the risk of ipsilateral lung cancer in patients with breast cancer (RR = 1.27, p = 0.001).

CONCLUSIONS

Patients with breast cancer are more likely to develop lung cancer than the general population, and the risk of developing primary lung cancer after breast cancer is affected by smoking, radiotherapy, chemotherapy, estrogen receptor status and progesterone receptor status.

Risk of primary lung cancer after adjuvant radiotherapy in breast cancer-a large population-based study

Adjuvant radiotherapy (RT) for breast cancer (BC) has been associated with an increased risk of later radiation-induced lung cancer (LC). We examined the risk of primary LC in a population-based cohort of 52300 women treated for BC during 1992 to 2012, and 253796 age-matched women without BC. Cumulative incidence of LC was calculated by the Kaplan-Meier method, and the risk of LC after BC treatment was estimated by Cox proportional hazards regression analyses. Women with BC receiving RT had a higher cumulative incidence of LC compared to women with BC not receiving RT and women without BC. This became apparent 5 years after RT and increased with longer follow-up. Women with BC receiving RT had a Hazard ratio of 1.59 (95% confidence interval 1.37-1.84) for LC compared to women without BC. RT techniques that lower the incidental lung doses, e.g breathing adaption techniques, may lower this risk.

Intensity Modulated Radiation Therapy (IMRT) With Simultaneously Integrated Boost Shortens Treatment Time and Is Noninferior to Conventional Radiation Therapy Followed by Sequential Boost in Adjuvant Breast Cancer Treatment: Results of a Large Randomized Phase III Trial (IMRT-MC2 Trial)

PURPOSE

In the modern era, improvements in radiation therapy techniques have paved the way for simultaneous integrated boost irradiation in adjuvant breast radiation therapy after breast conservation surgery. Nevertheless, randomized trials supporting the noninferiority of this treatment to historical standards of care approach are lacking.

METHODS

A prospective, multicenter, randomized phase 3 trial (NCT01322854) was performed to analyze noninferiority of conventional fractionated intensity modulated radiation therapy with simultaneous integrated boost (IMRT-SIB) to 3-D conformal radiation therapy with sequential boost (3-D-CRT-seqB) for breast cancer patients. Primary outcomes were local control (LC) rates at 2 and 5 years (noninferiority margin at hazard ratio [HR] of 3.5) as well as cosmetic results 6 weeks and 2 years after radiation therapy (evaluated via photo documentation calculating the relative breast retraction assessment [pBRA] score [noninferiority margin of 1.25]).

RESULTS

A total of 502 patients were randomly assigned from 2011 to 2015. After a median follow-up of 5.1 years, the 2-year LC for the IMRT-SIB arm was noninferior to the 3-D-CRT-seqB arm (99.6% vs 99.6%, respectively; HR, 0.602; 95% CI, 0.123-2.452; P = .487). In addition, noninferiority was also shown for cosmesis after IMRT-SIB and 3-D-CRT-seqB at both 6 weeks (median pBRA, 9.1% vs 9.1%) and 2 years (median pBRA, 10.4% vs 9.8%) after radiation therapy (95% CI, -0.317 to 0.107 %; P = .332). Cosmetic assessment according to the Harvard scale by both the patient and the treating physician as well as late-toxicity evaluation with the late effects normal tissues- subjective, objective, management, analytic criteria, a score for the evaluation of long-term adverse effects in normal tissue, revealed no significant differences between treatment arms. In addition, there was no difference in overall survival rates (99.6% vs 99.6%; HR, 3.281; 95% CI: -0.748 to 22.585; P = .148) for IMRT-SIB and 3-D-CRT-seqB, respectively.

CONCLUSIONS

To our knowledge, this is the first prospective trial reporting the noninferiority of IMRT-SIB versus 3-D-CRT-seqB with respect to cosmesis and LC at 2 years of follow-up. This treatment regimen considerably shortens adjuvant radiation therapy times without compromising clinical outcomes.

Clinic image surveillance reduces mortality in patients with primary hepato-gastrointestinal cancer who develop second primary lung cancer: A STROBE-compliant retrospective study

Second primary cancer is prevalent in patients with gastrointestinal (GI) cancer, for which lung cancer is the most common and associated with high lethality. Image screening for lung cancer was proved to be effective in early diagnosis and lower mortality. However, trials of screen for lung cancer generally excluded patients with a previous diagnosis of malignancy. The study aimed to investigate the outcome of second primary lung cancer and the factor that improve survival in patients with hepato-GI cancer.A total of 276 patients with secondary lung cancer were found among 3723 newly-diagnosed lung cancer patients diagnosed in Chang Gung Memorial Hospital, between 2010 and 2014. Patients' clinical characteristics, stages and survival were recorded and analyzed. The patients were separated into 2 groups: Group I was defined as lung cancer detected in original primary cancer clinic and group II patients defined as lung cancer detected in other medical places.Sixty-nine cases with primary GI-hepatic and secondary lung cancer were diagnosed (42 (60.8%) in Group I and 27 (39.1%) in Group II). Although both groups had comparable primary cancer stages and treatment, more patients in Group I than Group II were diagnosed as early stage lung cancer (stage I-II: 40.5% vs 11.1%; P = .023). Group II had larger lung tumor sizes than Group I (4.7 vs 3.5 cm; P = .025). Group I showed better 5-year overall survival than Group II (P = .014, median survival: 27 vs 10 months). Among Group II, only 37% had received image follow up in clinic compared with 67% of Group I cases (P = .025). Patients with chest image follow up in clinics also had better 5-year overall survival (P = .043).GI-hepatic cancer was the most common primary malignancy in the lung cancer cohort. Patients had better survival outcome when secondary lung cancer was diagnosed in original primary cancer clinic. Chest image screening strategy may contribute better survival in secondary lung cancer due to detection at an earlier stage.

The impact of smoking on adjuvant breast cancer radiation treatment: A systematic review

BACKGROUND

The influence of cigarette smoking on cancer risk has been well-studied. Similarly, exposure to ionizing radiation from radiotherapy (RT) can produce detrimental effects on an individual's health. In patients administered RT, there has been an observed relationship in other primary carcinomas. The purpose of this systematic review was to summarize the influence of cigarette smoking on outcomes post adjuvant RT in breast cancer patients.

METHODS

OVID Medline, Cochrane and Embase were searched and 1893 articles were identified. A total of 71 articles were included in the review. Study type, published year and sample size, age, systemic therapies, RT techniques and treatment side effects were collected if available.

RESULTS

The review found 198 different outcomes which fell into 7 categories and similar outcomes were recorded. 40% of skin reaction outcomes, 50% of cardiovascular outcomes, 71% of reconstruction outcomes, 29% of pulmonary function outcomes, 33% of mortality outcomes and 42% of secondary recurrence outcomes reported significant differences between smokers and non-smokers. None of the articles reported non-smokers to have a higher risk than smokers.

CONCLUSION

Cigarette smoking can pose a higher risk of post-treatment complications that can influence an individual's quality of life, survival rate and/or recurrence risk. This review further assessed the impact of smoking on various patient outcomes and side-effects in the adjuvant breast RT setting. The information provided in this review suggest that smoking cessation programs would help educate patients to understand their risks of being a current or former smoker when undergoing RT.

Chemical composition, antitumor and antioxidant effects of four lebanese plants extracts on human pulmonary adenocarcinoma

Lung cancer leading cause of humans' cancer-related death remains incurable with current drug therapies having many side-effects. Finding new natural cancer remedies would help design better therapies. This study aims to investigate the anticancer and antioxidant effects of the Levant endemic plants Prango sasperula, Stachys ehrenbergii, Hirtellina lobelia, and Salvia multicaulis on human pulmonary adenocarcinoma. GC/MS and NMR analyzed the bioactive compounds of methanolic extracts of these plants. Their antioxidant effect was measured by ABTS assay. The effect of these extracts on the viability of A549 (Human lung adenocarcinoma cell line) and NHBE (Normal Human Bronchial Epithelial Cells) was examined using MTT and Anchorage-Independent Colony Formation assays. Our findings show an interesting, specific cytotoxic effect of these plant extracts on A549 cells. Additionally, S. ehrenbergii and H. lobelii present a specific high alkylation potential. Data reveal an interesting antitumor potential attributed to their antiproliferative and alkylation actions towards human pulmonary adenocarcinoma.

A review of the effects of tobacco smoking on cancer treatment: smoking cessation intervention should be integrated into the cancer care continuum

Background:

The adverse health effects associated with smoking tobacco have been well investigated, and its detrimental effects on cancer treatment outcomes, efficacy and quality of life (QOL) for cancer patients have also been well documented. Tobacco smoke contains many thousands of chemicals, including a plethora of carcinogens, and the exposure of human cells to these carcinogens, and their metabolic activation, is the main mechanism by which smoking-related cancer is initiated.

Materials and Methods:

This paper reports on a narrative review of recent studies in the field of effects of tobacco smoking on cancer treatment, including the effects of carcinogens in smoke on carcinogenesis, cell mutations and the immune system. The health effects of smokeless tobacco, effects of tobacco smoking on cancer treatment, and its impact on surgery, radiation therapy and chemotherapy are reported. The potential risks of second primary cancers or recurrence from tobacco use, the effects of second-hand smoking and cancer treatment, the impact of smoking on the QOL after cancer treatment and the need to integrate smoking cessation programs into the cancer care continuum are also reported.

Conclusions:

Tobacco use has a direct impact on cellular function by inhibiting apoptosis, stimulating proliferation and decreasing the efficacy of cancer treatment; therefore, quitting its use has the potential to improve treatment response rates and survival, as well as reduces the risk of developing second cancers and potentially improves the QOL after treatment. Smoking cessation is one of the most important interventions to prevent cancer and is also essential after the diagnosis of cancer to improve clinical outcomes. Due to the numerous benefits of smoking cessation, it should become a critical component of the cancer care continuum in all oncology programs – from prevention of cancer through diagnosis, treatment, survivorship and palliative care. Evidence-based smoking cessation intervention should be sustainably integrated into any comprehensive cancer program, and the information should be targeted to the specific benefits of cessation in cancer patients.

Tobacco smoking after diagnosis of cancer: clinical aspects

Tobacco smoking accounts for at least 30% of all cancer deaths and nearly 90% of lung cancer deaths. Smoking cessation significantly reduces the risk of developing tobacco-related malignancies. Smoking after cancer diagnosis is also associated with multiple risks, including worse tolerance of treatment, higher risk of a failure and second primary tumors, and poorer quality of life. Apart from disease site and stage, continued smoking is considered the strongest adverse predictor of survival in cancer patients. However, the benefits of smoking cessation are undervalued: many patients are not aware of harms related to continued tobacco use after cancer diagnosis. Furthermore, health care professionals often do not encourage their patients to quit, and do not provide tobacco cessation assistance for continuing tobacco users. Despite the apparent impact of tobacco use on treatment outcomes, data on current smoking status is only rarely captured in clinical trials This article reviews the most important clinical aspects of smoking after the diagnosis of cancer.

Left-sided breast cancer and risks of secondary lung cancer and ischemic heart disease : Effects of modern radiotherapy techniques

PURPOSE

Modern breast cancer radiotherapy techniques, such as respiratory-gated radiotherapy in deep-inspiration breath-hold (DIBH) or volumetric-modulated arc radiotherapy (VMAT) have been shown to reduce the high dose exposure of the heart in left-sided breast cancer. The aim of the present study was to comparatively estimate the excess relative and absolute risks of radiation-induced secondary lung cancer and ischemic heart disease for different modern radiotherapy techniques.

METHODS

Four different treatment plans were generated for ten computed tomography data sets of patients with left-sided breast cancer, using either three-dimensional conformal radiotherapy (3D-CRT) or VMAT, in free-breathing (FB) or DIBH. Dose-volume histograms were used for organ equivalent dose (OED) calculations using linear, linear-exponential, and plateau models for the lung. A linear model was applied to estimate the long-term risk of ischemic heart disease as motivated by epidemiologic data. Excess relative risk (ERR) and 10-year excess absolute risk (EAR) for radiation-induced secondary lung cancer and ischemic heart disease were estimated for different representative baseline risks.

RESULTS

The DIBH maneuver resulted in a significant reduction of the ERR and estimated 10-year excess absolute risk for major coronary events compared to FB in 3D-CRT plans (p = 0.04). In VMAT plans, the mean predicted risk reduction through DIBH was less pronounced and not statistically significant (p = 0.44). The risk of radiation-induced secondary lung cancer was mainly influenced by the radiotherapy technique, with no beneficial effect through DIBH. VMAT plans correlated with an increase in 10-year EAR for radiation-induced lung cancer as compared to 3D-CRT plans (DIBH p = 0.007; FB p = 0.005, respectively). However, the EARs were affected more strongly by nonradiation-associated risk factors, such as smoking, as compared to the choice of treatment technique.

CONCLUSION

The results indicate that 3D-CRT plans in DIBH pose the lowest risk for both major coronary events and secondary lung cancer.

Dosimetric Considerations in Respiratory-Gated Deep Inspiration Breath-Hold for Left Breast Irradiation

PURPOSE

To present our clinical workflow of incorporating AlignRT for left breast deep inspiration breath-hold treatments and the dosimetric considerations with the deep inspiration breath-hold protocol.

MATERIAL AND METHODS

Patients with stage I to III left-sided breast cancer who underwent lumpectomy or mastectomy were considered candidates for deep inspiration breath-hold technique for their external beam radiation therapy. Treatment plans were created on both free-breathing and deep inspiration breath-hold computed tomography for each patient to determine whether deep inspiration breath-hold was beneficial based on dosimetric comparison. The AlignRT system was used for patient setup and monitoring. Dosimetric measurements and their correlation with chest wall excursion and increase in left lung volume were studied for free-breathing and deep inspiration breath-hold plans.

RESULTS

Deep inspiration breath-hold plans had significantly increased chest wall excursion when compared with free breathing. This change in geometry resulted in reduced mean and maximum heart dose but did not impact lung V₂₀ or mean dose. The correlation between chest wall excursion and absolute reduction in heart or lung dose was found to be nonsignificant, but correlation between left lung volume and heart dose showed a linear association. It was also identified that higher levels of chest wall excursion may paradoxically increase heart or lung dose.

CONCLUSION

Reduction in heart dose can be achieved for many left-sided breast and chest wall patients using deep inspiration breath-hold. Chest wall excursion as well as left lung volume did not correlate with reduction in heart dose, and it remains to be determined what metric will provide the most optimal and reliable dosimetric advantage.

[Systematizing support in cessation smoking to improve care for cancer patients]

Approximately 20% of cancer patients smoke at diagnosis (all localizations included), and over two thirds continue despite the therapeutic management of their cancer, especially when cancer is not associated with tobacco. The impact of smoking on quality of care for patients is actually not enough considered. A literature review conducted by the French National Cancer Institute emphasizes the importance of tobacco cessation to improve the prognosis (decreased mortality from all causes and specific); to reduce the risk of second primary cancers; to reduce per- and post-surgical risks as long as some toxicities related to treatments and to improve the quality of physical and mental life of patients. It is important that a communication with the patient takes place at the beginning of the treatment to impact the smoking behavior. All oncology health professionals should deliver a clearly and personalized cessation advice in the light of scientific data and ensure that smoking cessation help will be offered to the patient.

WITHDRAWN: Patients with lung cancer: Are electronic cigarettes harmful, useful?

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Differential expression of immunohistochemical markers in primary lung and breast cancers enriched for triple-negative tumours

AIMS

In breast cancer patients presenting with a lung lesion, the distinction between lung and breast origin is clinically important. Lung and breast cancers are both CK7(+) /CK20(-) , so additional immunohistochemical markers are needed.

METHODS AND RESULTS

We examined the expression of oestrogen receptor (ER), progesterone receptor (PR), thyroid transcription factor-1 (TTF-1), gross cystic disease fluid protein-15 (GCDFP-15), p63 and Wilms' tumour 1 (WT1) in a series of tissue microarrays comprising 266 non-small-cell lung cancers and 837 primary breast cancers enriched for triple-negative tumours (TNBC). Staining for ER, PR, TTF-1 and GCDFP-15 was present in 63%, 49%, 0% and 25% of breast and 6%, 9%, 59% and 1% of lung cancers, respectively. Strong staining for p63 was present in 63 (97%) lung squamous cell carcinomas and only eight (9%) TNBC. WT1 nuclear staining was rare; however, cytoplasmic staining was identified in 49 (40%) TNBC and 10 (5%) lung cancers. Cluster analysis segregated TNBC from lung cancers with TTF-1 and/or p63 staining favouring lung origin, and GCDFP-15 or WT1 staining favouring breast origin. Cancers negative for all four markers (17%) were 60% breast and 40% lung origin.

CONCLUSION

An immunohistochemical panel incorporating ER, TTF-1, GCDFP-15, p63 and WT1 can help to distinguish lung cancer from metastatic breast cancer, including TNBC.

Multiple primary cancers involving lung cancer at a single tertiary hospital: Clinical features and prognosis

Background

The development of other primary cancers in patients with lung cancer is unfortunate and uncommon, although the frequency is increasing. The aim of this study was to determine the clinical features and prognosis in patients with multiple primary cancers (MPC) involving lung cancer.

Methods

After a retrospective review of 1644 patients who were newly diagnosed with primary lung cancer between 1998 and August 2012 at a tertiary hospital, 105 patients were included.

Results

The median age at the time of lung cancer diagnosis was 67 years, and 68 patients were male. Synchronous primary cancers occurred in 47% of the study population (49/105). Among those with metachronous cancer (56/105), the median interval between the diagnosis of lung cancer and another malignancy was 47.1 months; 21 patients were diagnosed with lung cancer as the first primary tumor. The most frequent type of other malignancy was urogenital (30%), followed by gastrointestinal (30%) and thyroid malignancies (16%). Advanced stage of lung cancer (hazard ratio (HR), 3.2; 95% confidence interval (CI), 1.8–5.7; P < 0.001), supportive care only as treatment for lung cancer (HR, 2.8; 95% CI, 1.3–6.0; P = 0.006), and head and neck cancer as another malignancy (HR, 3.9; 95% CI, 1.4–10.8; P = 0.010) were independent predictors of shorter survival from the time of diagnosis of the second primary cancer.

Conclusion

Advanced lung cancer stage, symptomatic supportive care only without antitumor therapy for lung cancer, and head and neck cancer as another primary malignancy were poor prognostic factors in patients with MPC involving primary lung cancer.

Tobacco use in the oncology setting: advancing clinical practice and research

Although tobacco is a well-established causal agent for many human cancers, less emphasis has been placed on translating this evidence by evaluating the effects of continued tobacco use after a cancer diagnosis. A broad assessment of the effects of continued tobacco use demonstrates that tobacco increases cancer treatment toxicity, recurrence, second primary tumors, and mortality in patients with cancer. Few studies report the potential benefits of cessation after a cancer diagnosis, but data suggest improved treatment outcomes in patients with cancer who quit smoking. Improving tobacco cessation treatment efficacy and access to cessation support has been sparsely researched in the oncology setting compared with the general population; however, patients with cancer are receptive to standard evidence-based tobacco cessation guidelines. Several studies demonstrate moderate tobacco cessation success in patients with cancer using the general principles of evidence-based tobacco cessation support. Several systems-level issues and research efforts are needed to standardize tobacco use definitions, increase access to tobacco cessation support, improve tobacco cessation efficacy, understand the time-dependent effects of tobacco and cessation on cancer biology, and realize the potential benefits of tobacco cessation for patients with cancer.

Lung adenocarcinoma in a patient with plasmacytoma

An increased risk of second malignancy is well recognized in patients treated for plasma cell neoplasms. However, second solid tumor is very rare in such patients. We report a case of a 68-year-old woman with plasmacytoma who developed lung adenocarcinoma.

Risk of second primary cancer after breast cancer treatment

Technological advances in both diagnosis and treatment of breast cancer lead to early detection and better treatment management. Consequently, the population of long-term survivors is on the rise. The risk of developing second cancers among breast cancer survivors was shown to be higher than that for the general population. The aim of this work was to review the literature on the risk of second primary cancer (SPC) after breast irradiation. Pubmed search of population-based studies on SPC after breast irradiation was conducted and the findings (in terms of Standardised Incidence Ratio) were collated and discussed. Several studies confirmed the link between breast tumour irradiation and risk of SPC, showing a small, but valid risk. There are, however, confounding factors that can either underestimate or overestimate risks: misclassification of tumour status, genetic inheritance, smoking, environmental factors, and the lack of accurate data in cancer registries. While isolating these potential triggers might be difficult, this approach would allow better discernability between radiotherapy-related risks and those generated by other factors. It is also important to evaluate the current status of treatment-related late effects and to lower such risks by minimising the dose delivered to normal tissues.

Epidemiology of lung cancer

Incidence and mortality attributed to lung cancer has risen steadily since the 1930s. Efforts to improve outcomes have not only led to a greater understanding of the etiology of lung cancer, but also the histologic and molecular characteristics of individual lung tumors. This article describes this evolution by discussing the extent of the current lung cancer epidemic including contemporary incidence and mortality trends, the risk factors for development of lung cancer, and details of promising molecular targets for treatment.

Assessing tobacco use by cancer patients and facilitating cessation: an American Association for Cancer Research policy statement

When diagnosed with cancer, patients can immediately make a meaningful positive impact on their health by stopping their tobacco use. Scientific evidence clearly shows that tobacco use in patients with cancer leads to poorer outcomes. The specific biological processes driving tobacco consumption's interference in cancer therapy are the subject of continuing research, but the evidence is clear that tobacco use in patients with cancer leads to decreased treatment efficacy and safety, decreased survival, decreased quality of life, increased treatment-related toxicity, and increased risk of cancer recurrence and second primary tumors. Data suggest that tobacco cessation can improve outcomes and survival in patients with cancer, yet full execution of evidence-based cessation interventions is infrequent in oncology settings. Therefore, both improved provision of cessation assistance to all patients with cancer who use tobacco or have recently quit and further study of the deleterious effects of tobacco use and benefits of tobacco cessation on cancer progression and treatment are needed and recommended by the American Association for Cancer Research. Progress on both fronts begins with universal assessment and documentation of tobacco use as a standard of quality cancer care regardless of treatment setting and will be further facilitated through the development of reliable, valid, and standard measures of tobacco use, incorporation of evidence-based procedures into quality and accreditation procedures, and the development of appropriate training, clinical infrastructure, and incentives for delivery of tobacco cessation interventions.

Second primary cancers after adjuvant radiotherapy in early breast cancer patients: a national population based study under the Danish Breast Cancer Cooperative Group (DBCG)

BACKGROUND AND PURPOSE

To analyze the long-term risk of second primary solid non-breast cancer in a national population-based cohort of 46,176 patients treated for early breast cancer between 1982 and 2007.

PATIENTS AND METHODS

All patients studied were treated according to the national guidelines of the Danish Breast Cancer Cooperative Group. The risk of second primary cancers was estimated by Standardised incidence ratios (SIRs) and multivariate Cox regression models were used to estimate adjusted hazard ratios (HR) among irradiated women compared to non-irradiated. All irradiated patients were treated on linear accelerators. Second cancers were a priori categorized into two groups; radiotherapy-associated- (oesophagus, lung, heart/mediastinum, pleura, bones, and connective tissue) and non-radiotherapy-associated sites (all other cancers).

RESULTS

2358 second cancers had occurred during the follow-up. For the radiotherapy-associated sites the HR among irradiated women was 1.34 (95% CI 1.11-1.61) with significantly increased HRs for the time periods of 10-14 years (HR 1.55; 95% CI 1.08-2.24) and ≥ 15 years after treatment (HR 1.79; 95% CI 1.14-2.81). There was no increased risk for the non-radiotherapy-associated sites (HR 1.04; 95% CI 0.94-1.1). The estimated attributable risk related to radiotherapy for the radiotherapy-associated sites translates into one radiation-induced second cancer in every 200 women treated with radiotherapy.

CONCLUSIONS

Radiotherapy treated breast cancer patients have a small but significantly excess risk of second cancers.

Nicotine and lung cancer

Tobacco use in cancer patients is associated with increased cancer treatment failure and decreased survival. Nicotine is one of over 7,000 compounds in tobacco smoke and nicotine is the principal chemical associated with addiction. The purpose of this article is to review the tumor promoting activities of nicotine. Nicotine and its metabolites can promote tumor growth through increased proliferation, angiogenesis, migration, invasion, epithelial to mesenchymal transition, and stimulation of autocrine loops associated with tumor growth. Furthermore, nicotine can decrease the biologic effectiveness of conventional cancer treatments such as chemotherapy and radiotherapy. Common mechanisms appear to involve activation of nicotinic acetylcholine receptors and beta-adrenergic receptors leading to downstream activation of parallel signal transduction pathways that facilitate tumor progression and resistance to treatment. Data suggest that nicotine may be an important mechanism by which tobacco promotes tumor development, progression, and resistance to cancer treatment.

Bayesian sensitivity analysis methods to evaluate bias due to misclassification and missing data using informative priors and external validation data

BACKGROUND

Recent research suggests that the Bayesian paradigm may be useful for modeling biases in epidemiological studies, such as those due to misclassification and missing data. We used Bayesian methods to perform sensitivity analyses for assessing the robustness of study findings to the potential effect of these two important sources of bias.

METHODS

We used data from a study of the joint associations of radiotherapy and smoking with primary lung cancer among breast cancer survivors. We used Bayesian methods to provide an operational way to combine both validation data and expert opinion to account for misclassification of the two risk factors and missing data. For comparative purposes we considered a "full model" that allowed for both misclassification and missing data, along with alternative models that considered only misclassification or missing data, and the naïve model that ignored both sources of bias.

RESULTS

We identified noticeable differences between the four models with respect to the posterior distributions of the odds ratios that described the joint associations of radiotherapy and smoking with primary lung cancer. Despite those differences we found that the general conclusions regarding the pattern of associations were the same regardless of the model used. Overall our results indicate a nonsignificantly decreased lung cancer risk due to radiotherapy among nonsmokers, and a mildly increased risk among smokers.

CONCLUSIONS

We described easy to implement Bayesian methods to perform sensitivity analyses for assessing the robustness of study findings to misclassification and missing data.

Predicting the risk of secondary lung malignancies associated with whole-breast radiation therapy

PURPOSE

The risk of secondary lung malignancy (SLM) is a significant concern for women treated with whole-breast radiation therapy after breast-conserving surgery for early-stage breast cancer. In this study, a biologically based secondary malignancy model was used to quantify the risk of secondary lung malignancies (SLMs) associated with several common methods of delivering whole-breast radiation therapy (RT).

METHODS AND MATERIALS

Both supine and prone computed tomography simulations of 15 women with early breast cancer were used to generate standard fractionated and hypofractionated whole-breast RT treatment plans for each patient. Dose-volume histograms (DVHs) of the ipsilateral breast and lung were calculated for each patient on each plan. A model of spontaneous and radiation-induced carcinogenesis was used to determine the relative risks of SLMs for the different treatment techniques.

RESULTS

A higher risk of SLMs was predicted for supine breast irradiation when compared with prone breast irradiation for both the standard fractionation and hypofractionation schedules (relative risk [RR] = 2.59, 95% confidence interval (CI) = 2.30-2.88, and RR = 2.68, 95% CI = 2.39-2.98, respectively). No difference in risk of SLMs was noted between standard fractionation and hypofractionation schedules in either the supine position (RR = 1.05, 95% CI = 0.97-1.14) or the prone position (RR = 1.01, 95% CI = 0.88-1.15).

CONCLUSIONS

Compared with supine whole-breast irradiation, prone breast irradiation is associated with a significantly lower predicted risk of secondary lung malignancy. In this modeling study, fractionation schedule did not have an impact on the risk of SLMs in women treated with whole-breast RT for early breast cancer.

Tobacco assessment in actively accruing National Cancer Institute Cooperative Group Program Clinical Trials

PURPOSE

Substantial evidence suggests that tobacco use has adverse effects on cancer treatment outcomes; however, routine assessment of tobacco use has not been fully incorporated into standard clinical oncology practice. The purpose of this study was to evaluate tobacco use assessment in patients enrolled onto actively accruing cancer clinical trials.

METHODS

Protocols and forms for 155 actively accruing trials in the National Cancer Institute's (NCI's) Clinical Trials Cooperative Group Program were evaluated for tobacco use assessment at enrollment and follow-up by using a structured coding instrument.

RESULTS

Of the 155 clinical trials reviewed, 45 (29%) assessed any form of tobacco use at enrollment, but only 34 (21.9%) assessed current cigarette use. Only seven trials (4.5%) assessed any form of tobacco use during follow-up. Secondhand smoke exposure was captured in 2.6% of trials at enrollment and 0.6% during follow-up. None of the trials assessed nicotine dependence or interest in quitting at any point during enrollment or treatment. Tobacco status assessment was higher in lung/head and neck trials as well as phase III trials, but there was no difference according to year of starting accrual or cooperative group.

CONCLUSION

Most actively accruing cooperative group clinical trials do not assess tobacco use, and there is no observable trend in improvement over the past 8 years. Failure to incorporate standardized tobacco assessments into NCI-funded Cooperative Group Clinical Trials will limit the ability to provide evidence-based cessation support and will limit the ability to accurately understand the precise effect of tobacco use on cancer treatment outcomes.

Importance of hemoglobin concentration and its modification for the outcome of head and neck cancer patients treated with radiotherapy

INTRODUCTION

Hypoxia induced radioresistance has been acknowledged for decades. One of the indirect evidences of the influence of hypoxia on radiation response comes from the observations of a correlation between tumor control and hemoglobin level. This review examines the clinical data on the prognostic and predictive role of hemoglobin level and hemoglobin manipulation in radiotherapy of squamous cell carcinomas of the head and neck, a tumor type where hypoxic radioresistance have been previously documented.

THE INFLUENCE OF HEMOGLOBIN CONCENTRATION ON TUMOR OXYGENATION AND OUTCOME

The aim is to evaluate the existing literature for information of the influence of hemoglobin concentration and hemoglobin modifications on tumor oxygenation and outcome in head and neck squamous cell cancer patients. The data from several randomized trials show that while most studies have confirmed the prognostic value of hemoglobin, increasing the hemoglobin level through transfusion or erythropoietin stimulation did not result in improved outcome for patients with low initial hemoglobin levels. Clinical studies showed that smoking reduced the oxygen carrying capacity of the blood through formation of carboxyhemoglobin, and lead to poorer response to radiotherapy in smokers compared to non-smokers. Smoking also increased the risk of the development of secondary cancers.

CONCLUSION AND FUTURE PERSPECTIVES

In conclusion, low hemoglobin is a significant negative prognostic factor for radiotherapy of head and neck cancer. Correction of pre-treatment low hemoglobin by blood transfusion and/or erythropoietin stimulating agents does, however, not improve the outcome. Smoking leads to a decrease in effective hemoglobin and poorer treatment outcome. Smoking should be avoided in order to improve the therapeutic efficacy of radiotherapy and development of other smoking-related diseases and/or secondary cancers.

Cigarette smoking and outcomes after allogeneic hematopoietic stem cell transplantation

Abnormal lung function is a known risk factor for poor outcomes in the allogeneic hematopoietic stem cell transplantation (HSCT) population, although the specific causes of these abnormalities have not been well explored. There is limited data on the effect of cigarette smoking on transplantation outcomes. We conducted a retrospective observational cohort study of 845 consecutive patients age ≥ 18 years who underwent allogeneic HSCT at the Seattle Cancer Care Alliance/Fred Hutchinson Cancer Research Center. Smoking exposure was defined by quit time, smoking status (never, former, and current), and log(2)-transformed pack-years. The main outcomes were time to respiratory failure within 100 days of transplantation, relapse, and nonrelapse mortality. In multivariable analyses, a 2-fold increase in pack-years smoked was associated with an increased risk of early respiratory failure (hazard ratio [HR] 1.33, 95% confidence interval [CI] 1.09 to 1.64, P = .006). This association was observed independent of pretransplantation lung function. A 2-fold increase in pack-years smoked was associated with an increased risk of relapse, but this finding was not statistically significant (HR 1.16, 95% CI 0.92-1.46, P = .21). An association was not observed between cigarette smoking and nonrelapse mortality. Cigarette smoking is associated with an increased risk of respiratory failure and relapse within 100 days of allogeneic HSCT. The association with respiratory failure is mediated in part by abnormal lung function before transplantation and likely through other mechanisms as well. Given the adverse effects associated with cigarette smoking before transplantation, future studies should focus on obtaining accurate smoking histories, tracking prospective changes in smoking status, and assessing the benefits of tobacco cessation on outcomes in this population.

A study of immunohistochemical differential expression in pulmonary and mammary carcinomas

The risk of developing a second primary cancer is increased in patients with breast cancer, and the lung is one of the major sites involved. Moreover, the lung is the major metastatic site for breast cancers. A distinction between metastatic breast cancer and primary lung cancer can be histologically difficult, and both show an overlapping CK7+/CK20- immunoprofile in a majority of cases. The degree of difficulty increases with poorly differentiated tumors. We investigated differential expressions of TTF-1, Napsin A, surfactant apoprotein A, estrogen receptor, GATA-3, mammaglobin, and GCDFP-15 immunostains in 197 pulmonary carcinomas (158 adenocarcinomas, 39 squamous) and 115 invasive mammary carcinomas (91 ductal, 24 lobular type). In mammary carcinomas, estrogen receptor, GATA-3, mammaglobin, and GCDFP-15 were expressed in 74, 72, 64, and 62%, respectively, whereas TTF-1, Napsin A, and surfactant apoprotein A were all negative. The expressions were diffuse in estrogen receptor and GATA-3, and variable in mammaglobin and GCDFP-15. For a combination of estrogen receptor/mammaglobin or GATA-3/mammaglobin, 83% of mammary carcinomas were positive, and the detection rate was not improved by using all three markers. All lung squamous cell carcinomas were negative for all markers studied. TTF-1, Napsin A, and surfactant apoprotein A were positive in 80, 77, and 45% of pulmonary adenocarcinomas. None of the TTF-1-negative tumors expressed surfactant apoprotein A. GCDFP-15 was focally expressed in 2.5% of pulmonary adenocarcinomas, and estrogen receptor was focally expressed in one case (1.2%) of pulmonary adenocarcinoma. When metastasis from breast cancer is suspected in the lung, a combination of either estrogen receptor/mammaglobin or GATA-3/mammaglobin as breast markers, and a combination of TTF-1 and Napsin A as lung markers may be helpful for differentiating between the two. Caution should be taken in the interpretation of GCDFP-15 due to its occasional expression in pulmonary adenocarcinomas.

Secondary malignancies across the age spectrum

Development of a second malignancy is one of the most serious late effects in survivors of both childhood and adult-onset cancers. Patterns of second malignancy risk across the age spectrum can differ in terms of the types of second malignancies observed, magnitude of the risks, the latency period, associated risk factors, and modifying influences. Potential explanations for the varying risk patterns by age include differences in susceptibility of individual tissue/organ to carcinogenesis based on stage of development and level of tissue maturity, microenvironment, attained age, and lifestyle factors. A thorough understanding of these differences is essential when considering treatment modifications in newly diagnosed cancer patients who are aimed at reducing the risk of second malignancy and other late effects without compromising cure. Moreover, an understanding of the variations in second cancer risk according to age at treatment is important in customizing patient follow-up.

Modeling excess lung cancer risk among screened arm participants in the Mayo Lung Project

BACKGROUND

The Mayo Lung Project (MLP) was a randomized clinical trial designed to test whether periodic screening by chest x-ray reduced lung cancer (LC) mortality in men who were high-risk smokers. Among MLP participants, there were more deaths from LC in the screening arm both at the trial's end and after long-term follow-up. Overdiagnosis was cited widely as an explanation for the MLP results, whereas a role for excess LC risk attributable to undergoing numerous chest x-ray screenings largely was unexamined. The authors of this report examined the consistency of the MLP data with a modified 2-stage clonal expansion (TSCE) model of excess LC risk.

METHODS

By using a simulation model calibrated to the initial MLP data, the authors examined the expected statistical variance of LC incidence and mortality between the screening and control arms. A Bayesian estimation framework using a modified version of the TSCE model to evaluate the role of excess LC risk attributable to chest x-ray screening was derived and applied to the MLP data.

RESULTS

Simulation experiments indicated that the overall difference in LC deaths and incidence between the study arm and the control arm was unlikely (P = .0424 and P = .0104, respectively) assuming no excess risk of LC. The authors estimated that the 10-year excess LC risk for a man aged 60 years who smoked and who received 10 chest x-ray screenings was 0.574% (P = .0021).

CONCLUSIONS

The excess LC risk observed among screening arm participants was found to be statistically significant with respect to the TSCE model framework in part because of the incorporation of key risk correlates of age and screen frequency into the estimation framework.

Who's assessing tobacco use in cancer clinical trials?

INTRODUCTION

Clinical trials that do not collect data on tobacco use/exposure may not adequately assess the efficacy and effectiveness of experimental treatments.

METHODS

A cross-sectional study of interventional trials cited on ClinicalTrials.gov was undertaken that inquired of Local Project Directors from Connecticut guiding studies of breast, prostate, or colorectal cancer chemotherapy (N = 68) whether their protocols measured tobacco use by trial participants. Information pertaining to 46 trials (68%) is reported here. All but 1 were multicentered trials enrolling patients around the country.

RESULTS

Only 3 trials (7%) reported routine collection of tobacco use information at baseline and no trial reported monitoring tobacco use during treatment follow-up. None of the 3 trials collecting tobacco data reported using exposure information in analysis of treatment effects. Survey respondents suggested that uncertainty about the relevance of tobacco exposure to therapeutic efficacy, ambivalence about how to incorporate such data into analyses, insufficient resources for collecting such information, and uncertainty about the validity of assessment methods might be reasons why tobacco use is not routinely assessed.

DISCUSSION

Additional studies that address a fuller range of cancers, therapies, disease states, and clinical environments are needed to fully define the extent of this data lapse. Providing clinicians and trialists with appropriate tools for tobacco use assessment and encouraging them to collect such information about patients during treatment and follow-up may offer a simple cost-effective way to improve the quality and consequences of cancer care for every patient.

Lung cancer in never smokers: clinical epidemiology and environmental risk factors

More than 161,000 lung cancer deaths are projected to occur in the United States in 2008. Of these, an estimated 10 to 15% will be caused by factors other than active smoking, corresponding to 16,000 to 24,000 deaths annually. Thus lung cancer in never smokers would rank among the most common causes of cancer mortality in the United States if considered as a separate category. Slightly more than half of the lung cancers caused by factors other than active smoking occur in never smokers. As summarized in the accompanying article, lung cancers that occur in never smokers differ from those that occur in smokers in their molecular profile and response to targeted therapy. These recent laboratory and clinical observations highlight the importance of defining the genetic and environmental factors responsible for the development of lung cancer in never smokers. This article summarizes available data on the clinical epidemiology of lung cancer in never smokers, and several environmental risk factors that population-based research has implicated in the etiology of these cancers. Primary factors closely tied to lung cancer in never smokers include exposure to known and suspected carcinogens including radon, second-hand tobacco smoke, and other indoor air pollutants. Several other exposures have been implicated. However, a large fraction of lung cancers occurring in never smokers cannot be definitively associated with established environmental risk factors, highlighting the need for additional epidemiologic research in this area.

Pathological confirmation of primary lung cancer following breast cancer

PURPOSE

Studies have shown that women who survive breast cancer have an increased risk of a future primary lung cancer, though many are based only on data recorded in tumor registries and none have conducted pathological confirmation. Previous studies and future use of large registries may be affected by misdiagnosis.

METHODS

Pathological analysis was conducted on tumors from 110 women with breast cancer followed by lung cancer using morphology, Estrogen Receptor-alpha (ER), and Thyroid Transcription Factor-1 (TTF1). We developed an algorithm to classify lung tumors as unlikely lung cancer (score=1) to likely lung cancer (score=5).

RESULTS

Mean time to diagnosis of lung cancer after breast cancer was 13 years. 76% of breast tumors and 20% of lung tumors were positive for ER and 51% of lung tumors were positive for TTF-1. 86% of the lung tumors were probable primaries, 7% were probable metastases from the breast, and 7% were of undetermined status. 70% of probable metastases had a latency of longer than 10 years.

CONCLUSION

Prior studies identifying the association of breast cancer and breast cancer treatments with lung cancer are likely to reflect true associations not confounded by misdiagnosis, as evidenced by the low rate of misclassification detected in this study. Analysis of the years of diagnosis suggests that latency may not be an accurate criterion for assignment of primary status, which could be significant in a clinical setting. These data may also benefit future retrospective studies using large registries.

Long-term follow-up of the Stockholm randomized trials of postoperative radiation therapy versus adjuvant chemotherapy among 'high risk' pre- and postmenopausal breast cancer patients

For many years, loco-regional radiotherapy was the standard postoperative treatment for node positive breast cancer patients in Sweden. Because of encouraging results from trials of adjuvant chemotherapy in the mid 1970s, the Stockholm Breast Cancer Study Group decided to directly compare postoperative radiation (RT) with adjuvant CMF-type chemotherapy (CT). Long-term results are presented from two randomized trials of RT versus CT in pre- (n = 547) and postmenopausal (n = 679) patients, respectively, with node positive disease or a tumour diameter > 30 mm. RT substantially reduced loco-regional recurrences among both pre- and postmenopausal patients (relative hazard RT versus CT: 0.67 and 0.43, respectively). Among premenopausal patients distant metastases occurred less frequently in the CT group (relative hazard: 1.68, p > 0.001) resulting in an improved recurrence-free survival (p = 0.04). Overall survival was also better with CT (cumulative survival at 15 years: 50% and 44% in the CT and RT groups, respectively) but the difference was not statistically significant. Among the postmenopausal patients there were no substantial differences in terms of recurrence-free or overall survival between the treatment groups. The risk of a second primary malignancy, however, was doubled in the RT group (p > 0.01). The most pronounced excess concerned second lung cancers occurring after 10 years. The cumulative incidence at 20 years was estimated at 0.3% and 3.7% in the CT and RT groups, respectively. The trials illustrate the role of radiotherapy in preventing loco-regional recurrences among high-risk patients, as well as the need for systemic treatment to control the disease systemically.

Polycyclic aromatic hydrocarbon-DNA adducts and survival among women with breast cancer

Polycyclic aromatic hydrocarbons (PAH) are mammary carcinogens in animal studies, and a few epidemiologic studies have suggested a link between elevated levels of PAH-DNA adducts and breast cancer incidence. An association between PAH-DNA adducts and survival among breast cancer cases has not been previously reported. We conducted a survival analysis among women with newly diagnosed invasive breast cancer between 1996 and 1997, enrolled in the Long Island Breast Cancer Study Project. DNA was isolated from blood samples that were obtained from cases shortly after diagnosis and assayed for PAH-DNA adducts using ELISA. Among the 722 cases with PAH-DNA adduct measurements, 97 deaths (13.4%) from all causes and 54 deaths (7.5%) due to breast cancer were reported to the National Death Index (NDI) by December 31, 2002. Using Cox proportional hazards models and controlling for age at diagnosis, we did not find evidence that all-cause mortality (hazard ratio (HR)=0.88; 95% confidence interval (CI): 0.57-1.37), or breast cancer mortality (HR=1.20; 95% CI: 0.63-2.28) was strongly associated with detectable PAH-DNA adduct levels compared with non-detectable adducts; additionally, no dose-response association was observed. Among a subgroup with treatment data (n=520), adducts were associated with over a two-fold higher mortality among those receiving radiation, but mortality for adducts was reduced among hormone therapy users. Results from this large population-based study do not provide strong support for an association between detectable PAH-DNA adducts and survival among women with breast cancer, except perhaps among those receiving radiation treatment.

Effect of Breast Cancer Radiotherapy and Cigarette Smoking on Risk of Second Primary Lung Cancer

Purpose

Prior studies have found that postmastectomy radiotherapy (PMRT) for breast cancer (BC) increases the risk of lung cancer (LC). We explored the joint effects of cigarette smoking and PMRT on LC risk.

Methods

We conducted a population-based nested case-control study among women registered in the Connecticut Tumor Registry diagnosed with nonmetastatic BC between January 1, 1965 and December 31, 1989. Patient cases developed a LC ≥ 10 years after BC diagnosis. Controls were matched to patient cases on age, year of BC diagnosis, and length of survival. Medical records were reviewed for pathology, BC therapy, and smoking history. We used conditional logistic regression to estimate odds ratios for the independent and joint effects of smoking and PMRT on risk of overall, ipsilateral, and contralateral LC.

Results

Among 113 second primary LC patient cases and 364 controls, compared with nonsmoking women who did not receive PMRT, nonsmoking women who received PMRT had no higher risk of LC; adjusted odds ratios were 5.9 (95% CI, 2.7 to 12.8) for ever-smokers who did not receive PMRT and 18.9 (95% CI, 7.9 to 45.4) for ever-smokers who received PMRT. Adjusted odds ratios for the joint effects of smoking and PMRT were 10.5 (95% CI, 2.9 to 37.8) for the contralateral lung and 37.6 (95% CI, 10.2 to 139.0) for the ipsilateral lung. Smoking and PMRT were associated with increased risk for all histologic types of LC.

Conclusion

PMRT after a diagnosis of BC sharply increased the risk of second primary LC, especially in the ipsilateral lung, among ever-smokers. Clinicians should consider including smoking history in their discussions with patients about the risks and benefits of PMRT.