Metformin in Conjunction With Stereotactic Radiotherapy for Early-stage Non-small Cell Lung Cancer: Long-term Results of a Prospective Phase II Clinical Trial.

BACKGROUND/AIM: Non-small cell lung cancer (NSCLC) is increasingly detected in early stages and there is interest in improving outcomes with stereotactic body radiotherapy (SBRT). As metformin affects NSCLC signaling pathways, it might alter the metabolism of NSCLC treated with SBRT. This study investigated the long-term outcomes of a phase II clinical trial evaluating metformin in conjunction with SBRT for early-stage NSCLC. PATIENTS AND METHODS: The trial evaluated patients with American Joint Commission on Cancer (AJCC) 7th edition Stage I-II, cT1-T2N0M0 NSCLC who were randomized 6:1 to receive metformin versus placebo in conjunction with SBRT. The outcomes analyzed included local failure (LF), progression-free survival (PFS), overall survival (OS), and Common Terminology Criteria for Adverse Events (CTCAE) version 4 toxicities. RESULTS: There were 14 patients randomized to the metformin arm and one to the placebo. Median follow-up was four years. In the metformin group, the median PFS was 4.65 years [95% confidence interval (CI)=0.31-5.93] and median survival was 4.97 years (95%CI=3.05-4.61). Five year PFS was 27.8% (95%CI=5.3-57.3%) and OS was 46.0% (95%CI=16.0-71.9%). The one patient randomized to placebo was alive and without progression at five years. There were no LFs in the primary SBRT treatment volumes and no CTCAE version 4 Grade ≥3 adverse events. CONCLUSION: Outcomes of SBRT and metformin for early-stage NSCLC were similar to historic controls. These findings along with the results of the NRG-LU001 and OCOG randomized trials do not support the therapeutic use of metformin for NSCLC.

Adherence to the low-fat diet pattern reduces the risk of lung cancer in American adults aged 55 years and above: a prospective cohort study.

OBJECTIVES: There is little evidence on the association between low-fat dietary patterns and lung cancer risk among middle-aged and older adults. To fill this gap, we comprehensively investigated the association of adherence to a low-fat diet (LFD) and intake of different fat components including saturated, monounsaturated, and polyunsaturated fatty acids with incidence of lung cancer and its subtypes [non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC)] among adults aged 55 years and older. DESIGN: A prospective cohort study with a mean follow-up time of 8.8 years. SETTING AND PARTICIPANTS: This study used data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. The study population included 98,459 PLCO participants age 55 and over at baseline who completed food frequency questionnaires providing detailed dietary information and had no history of cancer. METHODS: Dietary intake was assessed using a validated food frequency questionnaire at baseline. A LFD score was calculated based on fat, protein, and carbohydrate intake as a percentage of total calories. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between LFD score and intake of fat components (in quartiles) and incident lung cancer and its subtypes over follow-up. Restricted cubic spline analyses were conducted to examine possible nonlinear relationships. Subgroup analyses were performed to evaluate potential effect modifiers, and several sensitivity analyses were conducted to assess the stability of the findings. RESULTS: During a follow-up of 869,807.9 person-years, 1,642 cases of lung cancer were observed, consisting of 1,408 (85.75%) cases of NSCLC and 234 (14.25%) cases of SCLC. The highest versus the lowest quartiles of the LFD score were found to be associated with a reduced risk of lung cancer (HR, 0.76; 95% CI, 0.66-0.89), NSCLC (HR, 0.79; 95% CI, 0.67-0.93), and SCLC (HR, 0.59; 95% CI, 0.38-0.92). The restricted cubic spline plots demonstrated a linear dose-response relationship between the LFD score and the risk of lung cancer as well as its subtypes. This risk reduction association for overall lung cancer was more pronounced in smokers (HR, 0.71; 95% CI, 0.60-0.84; P for interaction = 0.003). For fat components, high consumption of saturated fatty acids was associated with an increased lung cancer risk (HR, 1.35; 95% CI, 1.10-1.66), especially for SCLC (HR, 2.05; 95% CI, 1.20-3.53). No significant association was found between consumption of monounsaturated or polyunsaturated fatty acids and incident lung cancer and its subtypes. CONCLUSIONS: Our findings suggest that adherence to LFD may reduce the lung cancer risk, particularly in smokers; while high saturated fatty acids consumption may increase lung cancer risk, especially for SCLC, among middle-aged and older adults in the US population.

Stem cell and lung cancer development: blaming the Wnt, Hh and Notch signalling pathway

Primary lung cancer may arise from the central (bronchial) or peripheral (bronchiolo-alveolar) compartments. However the origins of the different histological types of primary lung cancer are not well understood. Stem cells are believed to be crucial players in tumour development and there is much interest in identifying those compartments that harbour stem cells involved in lung cancer. Although the role of stem cells in carcinogenesis is not well characterised, emerging evidence is providing new insights into this process. Numerous studies have indicated that lung cancer is not a result of a sudden transforming event but a multistep process in which a sequence of molecular changes result in genetic and morphological aberrations. The exact sequence of molecular events involved in lung carcinogenesis is not yet well understood, therefore deeper knowledge of the aberrant stem cell fate signalling pathway could be crucial in the development of new drugs against the advanced setting (AU)

Smoking habits in elderly lung cancer patients: still no changes in epidemiology? A single-center experience

PURPOSE: Our goal was to describe the clinical, histological, and epidemiological characteristics of lung cancer diagnoses in people ≥70 years of age. MATERIALS AND METHODS: Information on patients diagnosed with lung cancer from January 2006 to February 2008 was prospectively collected from the outpatient oncology department at a regional hospital. A total of 83 patients (97.6% men; mean age 77 years) were studied. There was a higher ratio of men to women than that reported in younger populations. Mean age was higher than that reported for randomized studies: 65.1% were ≥75 years old. Patients >80 years constituted 28.9% of the study population. Most patients (96.4%) had a history of smoking; they were predominantly former smokers (72.5% vs. 27.5%). RESULTS: The most common histological types were squamous cell (61.3%) and small cell (14.5%) carcinoma. Metastasis was present in 36.1% of patients. Stage was significantly associated with survival (logrank p < 0.001). There was no association between age and survival. Squamous cell lung cancer was associated with a better survival (p = 0.003). CONCLUSIONS: Elderly lung cancer patients who attended clinical practice were older than those included in prospective studies. The predominance of men and squamous cell carcinoma is associated with a smoking history. The epidemiological and histological patterns of younger patients have changed, possibly in relation to changes in smoking habits. The translation of these changes to elderly patients will be evidenced in the future. Only prospective epidemiologic studies will determine whether smoking habits are changing epidemiology in elderly lung cancer patients (AU)