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.

Role of Prophylactic Cranial Irradiation in Extensive-Stage Small Cell Lung Cancer.

Patients with small cell lung cancer (SCLC) are at significant risk of developing brain metastases during their disease course. Prophylactic cranial irradiation (PCI) has been incorporated into SCLC treatment guidelines to diminish the risk of developing brain metastases. In 2007, a randomized trial suggested that PCI decreases the incidence of brain metastases and prolongs overall survival (OS) in patients with extensive-stage SCLC (ES-SCLC) who have responded to initial therapy. However, this study did not include modern central nervous system imaging with CT or MRI prior to randomization. A more recent Japanese trial with MRI staging and surveillance demonstrated that PCI diminished the incidence of brain metastases but did not improve survival. This review examines the largest clinical studies, controversies, and future directions of PCI in patients with ES-SCLC.

Re-evaluation of prophylactic cranial irradiation in limited-stage small cell lung cancer: a propensity score matched analysis.

We attempted to re-evaluate the efficacy of prophylactic cranial irradiation (PCI) in limited-stage small cell lung cancer (LS-SCLC) with more recent data. A total of 179 patients with LS-SCLC received radical thoracic radiotherapy and chemotherapy at our institution between 1998 and 2018. One hundred twenty-eight patients who achieved complete response (CR), good partial response (PR), and PR without progression for at least for one year after initial therapy were enrolled in this study. These patients were divided into a PCI group (group A, n = 43), and a non-PCI group (group B, n = 85). Survival outcomes were retrospectively evaluated. Because several background factors differed significantly between groups A and B, propensity score (PS) matching was performed as 1:1 match of the two groups. Finally, we analyzed 64 patients (group A/B = 32/32). Median follow-up periods were 53 and 31 months in groups A and B, respectively. There were no significant differences between the groups' backgrounds. Two-year overall survival (OS) rates were 77% in group A and 62% in group B (p = 0.224). Two-year brain metastasis free survival (BMFS) rates were 85% in group A and 57% in group B (p = 0.008). The number of patients who underwent a brain imaging test for confirmation of no brain metastasis (BM) after radical thoracic radiotherapy and chemotherapy (before PCI) was 84 (group A/B = 32/52). A PS matched analysis for cases of pre-PCI brain imaging group, two-year OS rates for group A/B were 73/59% (p = 0.446). Two-year BMFS rates for group A/B were 91/52% (p = 0.021). Retrospectively, PS matched analysis revealed that adding PCI to LS-SCLC patients who achieved good thoracic control significantly improved BMFS, but OS did not improve.

Role of radiation in extensive stage small cell lung cancer: a National Cancer Database registry analysis.

The role of prophylactic cranial irradiation (PCI) and thoracic radiation therapy (TRT) in extensive-stage small cell lung cancer remains controversial. The authors examined the National Cancer Database and identified patients with extensive-stage small cell lung cancer with no brain metastasis. Patients were excluded if they died 30 days from diagnosis, did not receive polychemotherapy, had other palliative radiation or had missing information. A propensity score-matched analysis was also performed. A total of 21,019 patients were identified. The majority of patients did not receive radiation (69%), whereas 10% received PCI and 21% received TRT. The addition of PCI and TRT improved median survival and survival at 1 and 2 years (p ≤ 0.05). The propensity score-matched analysis confirmed the same overall survival benefit with both PCI and TRT. This registry-based analysis of >1500 accredited cancer programs shows that PCI and TRT are not commonly utilized for extensive-stage small cell lung cancer patients who are treated with multiagent chemotherapy. The addition of PCI and TRT significantly improves overall survival in this otherwise poor prognostic group. Further research is needed to confirm the role of PCI and TRT, especially in the era of improved systemic therapy.

Lay abstract The role of radiation therapy in patients with metastatic small cell lung cancer remains controversial. The authors examined the National Cancer Database and identified patients with metastatic small cell lung cancer without brain metastasis. Patients were excluded if they died 30 days from diagnosis, did not receive multiagent chemotherapy, had other palliative radiation or had missing information regarding treatment. A total of 21,019 patients were identified. The majority of patients did not receive radiation (69%), whereas 10% received radiation to the brain and 21% received radiation to their lungs. The addition of brain and lung radiation therapy improved median survival and survival at 1 and 2 years. The addition of prophylactic cranial irradiation and thoracic radiation therapy improves survival in extensive-stage small cell lung cancer. Future research is needed to evaluate the role of radiation in the era of chemoimmunotherapy.

Antireflux surgery and risk of lung cancer by histological type in a multinational cohort study.

INTRODUCTION: Airway micro-aspiration might contribute to the proposed associations between gastroesophageal reflux disease (GERD) and some lung diseases, including lung cancer. This study aimed to examine the hypothesis that antireflux surgery decreases the risk of small cell carcinoma, squamous cell carcinoma and adenocarcinoma of the lung differently depending on their location in relation to micro-aspiration. METHODS: Population-based cohort study including patients having undergone antireflux surgery during 1980-2014 in Denmark, Finland, Iceland, Norway or Sweden. Patients having undergone antireflux surgery were compared with two groups: 1) the corresponding background population, by calculating standardised incidence ratios (SIRs) with 95% confidence intervals (CIs) and 2) non-operated GERD-patients, by calculating hazard ratios (HRs) with 95% CIs using multivariable Cox regression with adjustment for sex, age, calendar period, country, chronic obstructive pulmonary disease and obesity diagnosis or type 2 diabetes. RESULTS: Among all 812,617 GERD-patients, 46,996 (5.8%) had undergone antireflux surgery. The SIRs were statistically significantly decreased for small cell carcinoma (SIR = 0.57, 95% CI 0.41-0.77) and squamous cell carcinoma (SIR = 0.75, 95% CI 0.60-0.92), but not for adenocarcinoma of the lung (SIR = 0.90, 95% CI 0.76-1.06). The HRs were also below unity for small cell carcinoma (HR = 0.63, 95% CI 0.44-0.90) and squamous cell carcinoma (HR = 0.80, 95% CI 0.62-1.03), but not for adenocarcinoma of the lung (HR = 1.03, 95% CI 0.84-1.26). Analyses restricted to patients with objective GERD (reflux oesophagitis or Barrett's oesophagus) showed similar results. CONCLUSIONS: This all-Nordic study indicates that patients who undergo antireflux surgery are at decreased risk of small cell carcinoma and squamous cell carcinoma of the lung, but not of adenocarcinoma of the lung.

Meta-analysis of prophylactic cranial irradiation or not in treatment of extensive-stage small-cell lung cancer: The dilemma remains.

PURPOSE: The role of prophylactic cranial irradiation (PCI) in treatment of extensive-stage small-cell lung cancer (SCLC) is controversial. The aim of this study was to systematically evaluate the efficacy and safety of using PCI in the treatment of extensive-stage SCLC. In the present study, we examined whether PCI was essential for the optimal treatment of extensive-disease small-cell lung cancer. MATERIAL AND METHODS: We searched the PubMed, Embase, Medline, and China National Knowledge Infrastructure databases to identify articles that assessed the efficacy of PCI in treating extensive-stage small-cell lung cancer patients. RESULTS: We identified 8 studies that involved a total of 982 patients who received PCI (PCI group) and a total of 4509 patients who did not receive PCI (control group). The results showed that PCI significantly improved the 1-year overall survival rate (HR=1.50; 95% CI: 1.23-1.82; I2=67%; P<0.0001) and reduced the incidence of brain metastasis (HR=0.46; 95% CI: 0.37-0.58; I2=6%; P<0.00001). CONCLUSION: PCI improves the 1-year overall survival rate and reduces the risk of brain metastasis in patients with extensive-stage SCLC.

Prolonged lung cancer screening reduced 10-year mortality in the MILD trial: new confirmation of lung cancer screening efficacy.

BACKGROUND: The National Lung Screening Trial showed that lung cancer (LC) screening by three annual rounds of low-dose computed tomography (LDCT) reduces LC mortality. We evaluated the benefit of prolonged LDCT screening beyond 5 years, and its impact on overall and LC specific mortality at 10 years. DESIGN: The Multicentric Italian Lung Detection (MILD) trial prospectively randomized 4099 participants, to a screening arm (n = 2376), with further randomization to annual (n = 1190) or biennial (n = 1186) LDCT for a median period of 6 years, or control arm (n = 1723) without intervention. Between 2005 and 2018, 39 293 person-years of follow-up were accumulated. The primary outcomes were 10-year overall and LC specific mortality. Landmark analysis was used to test the long-term effect of LC screening, beyond 5 years by exclusion of LCs and deaths that occurred in the first 5 years. RESULTS: The LDCT arm showed a 39% reduced risk of LC mortality at 10 years [hazard ratio (HR) 0.61; 95% confidence interval (CI) 0.39-0.95], compared with control arm, and a 20% reduction of overall mortality (HR 0.80; 95% CI 0.62-1.03). LDCT benefit improved beyond the 5th year of screening, with a 58% reduced risk of LC mortality (HR 0.42; 95% CI 0.22-0.79), and 32% reduction of overall mortality (HR 0.68; 95% CI 0.49-0.94). CONCLUSIONS: The MILD trial provides additional evidence that prolonged screening beyond 5 years can enhance the benefit of early detection and achieve a greater overall and LC mortality reduction compared with NLST trial. CLINICALTRIALS.GOV IDENTIFIER: NCT02837809.

The effects of prophylactic cranial irradiation versus control on survival of patients with extensive-stage small-cell lung cancer: a meta-analysis of 14 trials.

BACKGROUND: A recent Japanese study suggested prophylactic cranial irradiation (PCI) failed to improve survival of extensive-stage small-cell lung cancer (SCLC). However, previous studies showed that PCI was beneficial in reducing the rate of mortality for extensive-stage SCLC. In this study, we aimed to evaluate the impact of PCI on the survival of patients diagnosed with extensive-stage SCLC by meta-analysis. METHODS: PubMed, Embase, the Cochrane library and Chinese Biomedical Literature database (CBM) were systematically searched to identify eligible clinical studies assessing the efficacy of PCI in extensive-stage SCLC patients. After extracting survival data, brain metastasis, and response rates, the pooled estimates were calculated. RESULTS: A total of 14 clinical studies were included, involving 1221 cases in the PCI group and 5074 in the control group. The results showed that PCI significantly improved overall survival (Hazard ratio (HR) = 0.57; 95% confidence interval (CI): 0.47, 0.69; p < 0.001) and brain metastasis (risk ratio (RR) =0.47, 95%CI: 0.33, 0.69; p < 0.01). Subgroup analysis along with sensitivity analysis suggested that PCI effects on overall survival were independent of region, pre-PCI brain metastasis status and PCI administration timing. CONCLUSION: PCI improves overall survival in extensive-stage SCLC. More randomized controlled trials are needed to verify our findings.

Is prophylactic cranial irradiation (PCI) needed in patients with extensive-stage small cell lung cancer showing complete response to first-line chemotherapy?

Throughout the entire world, prophylactic cranial irradiation (PCI) is the standard care for patients with small cell lung cancer (SCLC) in whom a favorable therapeutic effect is achieved after front-line treatment, regardless of whether the disease is in the limited stage or extensive stage. In the EORTC study, PCI was shown to confer a survival benefit for patients with extensive-stage small cell lung cancer (ES-SCLC) who experienced any positive response after initial chemotherapy. However, the Japan study failed to confirm a survival benefit. As a result, the guidelines in Japan recommend that PCI should not be carried out in cases of ES-SCLC. Complete response (CR) subset analysis in the Japan study suggested that PCI did not provide a survival benefit for patients with ES-SCLC. PCI with a risk of adverse events has poor significance, even if the patients show CR to chemotherapy.

Is prophylactic cranial irradiation indicated for patients with extensive-stage small cell lung cancer with a complete response to first-line treatment?

Prophylactic cranial irradiation (PCI) has been considered standard of care for patients with limited-stage small-cell lung cancer who achieve complete response to definitive treatment after a meta-analysis revealed its favorable effects on survival. In a European trial, PCI was also shown to confer a survival advantage for patients with extensive-stage (ES) SCLC who experienced any positive response after initial chemotherapy, leading to PCI also being considered a standard treatment for these patients as well. However, a recent Japanese trial investigating PCI for patients with ES-SCLC was stopped early when an interim analysis failed to confirm a survival benefit. This finding has motivated the thoracic oncology community to rethink the role of PCI in ES-SCLC.

The role of prophylactic cranial irradiation for patients with small-cell lung cancer.

Small-cell lung cancer (SCLC) has a particular propensity to metastasize to the brain, affecting ~10% of SCLC patients at diagnosis, but may occur in more than 50% of 2-year survivors. Most cytotoxic drugs have limited ability to cross the blood-brain barrier, and the effectiveness of chemotherapy for brain metastasis is limited. Therefore, prophylactic cranial irradiation (PCI) has been proposed to treat SCLC. A meta-analysis revealed that PCI significantly decreased the risk of brain metastasis and increased the 3-year survival rate; it has been established as a standard therapy for limited-disease SCLC. However, certain aspects of PCI remain unclarified, including the roles in resected SCLC and extensive-disease SCLC, and its neurotoxicities. In addition, information on PCI has been obtained from old clinical trials without the use of new imaging devices, such as magnetic resonance imaging. Evidence from advanced imaging techniques is needed in this era.

Cost-Effectiveness of Thoracic Radiation Therapy for Extensive-Stage Small Cell Lung Cancer Using Evidence From the Chest Radiotherapy Extensive-Stage Small Cell Lung Cancer Trial (CREST).

PURPOSE: The Chest Radiotherapy Extensive-Stage Small Cell Lung Cancer Trial (CREST) showed that adding thoracic radiation therapy (TRT) to the standard treatment (ST) paradigm of chemotherapy and prophylactic cranial irradiation improves overall survival and progression-free survival (PFS) in patients with extensive-stage small cell lung cancer (ES-SCLC). We evaluated the cost-effectiveness of adding TRT to ST in ES-SCLC patients. METHODS AND MATERIALS: A cost-utility analysis was performed comparing TRT plus ST versus ST alone. The base-case time horizon was 24 months, consistent with the maximum PFS reported in the CREST. Overall survival was partitioned into 2 health states: PFS and postprogression survival. The proportion of patients in each health state over time was estimated by fitting parametric probability distributions to the CREST survival data. Costs were from a US health care payer perspective, and utilities were derived from the literature. Incremental cost-effectiveness ratios (ICERs) were calculated per quality-adjusted life-year (QALY) using a 3% discount rate. Sensitivity analyses addressed uncertainty in key variables. RESULTS: In the base-case analysis, adding TRT to ST was both cost saving and more effective, thereby strongly dominating ST alone. At willingness-to-pay thresholds of $50,000/QALY, $100,000/QALY, and $200,000/QALY, TRT was preferred 68%, 81%, and 96% of the time, respectively. In the lifetime scenario analysis, the TRT ICER increased to $194,726/QALY. CONCLUSIONS: By use of the actual follow-up interval reported in the CREST, adding TRT to ST strongly dominates a strategy of ST alone in ES-SCLC patients. Since the long-term survival benefit of TRT is small relative to ongoing costs of progressive metastatic disease, we estimate less favorable ICERs for TRT over a lifetime horizon.

Prophylactic Cranial Irradiation for Extensive Small-Cell Lung Cancer.

Small-cell lung cancer (SCLC) has a high predilection for metastasizing to the brain after chemotherapy. This has been blamed on the blood-brain barrier, which prevents chemotherapy from penetrating into the brain, thus creating a sanctuary site. It has been estimated that up to three quarters of patients with SCLC will eventually develop brain metastases. This led investigators to administer prophylactic cranial irradiation (PCI) to decrease this risk. Several trials were performed in patients with SCLC after initial therapy (chemotherapy with or without thoracic radiotherapy) that compared the outcomes of PCI versus no PCI. Early trials generally found that PCI significantly decreased the risk of brain metastases but did not significantly improve survival. These trials were re-evaluated in two larger meta-analyses that included patients with either limited-stage SCLC or extensive-stage SCLC (ESCLC). Both meta-analyses reported that PCI significantly decreased brain metastases and improved survival in patients who had a complete response following initial therapy. These studies were performed before the advent of modern imaging with computed tomography or magnetic resonance imaging (MRI). There have been two modern trials of PCI versus no PCI in patients with ESCLC and both found that PCI decreases brain metastases. The first did not include brain MRI before registration and found that PCI improved survival, whereas the second study did include MRI before registration and at frequent intervals thereafter. That trial found that PCI did not confer a survival advantage. This review will examine the evidence and provide recommendations regarding the role of PCI for patients with ESCLC.

Prospective Study of Hippocampal-Sparing Prophylactic Cranial Irradiation in Limited-Stage Small Cell Lung Cancer.

PURPOSE: To prospectively evaluate cognitive function and intracranial failure patterns after hippocampal-sparing prophylactic cranial irradiation (PCI) for limited-stage small cell lung cancer (SCLC). METHODS AND MATERIALS: Adults with limited-stage SCLC, achieving a complete response to chemoradiotherapy and no brain metastases, were eligible. Patients received PCI 25 Gy/10 fractions, with a mean hippocampal dose limited to <8 Gy and ≥90% of the brain receiving 90% of the prescription. A diverse battery of neuropsychological testing was performed at baseline and 6 and 12 months after PCI. Brain MRI scans were performed at baseline and 6, 12, 18, and 24 months. The primary endpoint was memory measured by the Hopkins Verbal Learning Test-Revised Delayed Recall at 6 months after PCI. The 25-Gy arm of Radiation Therapy Oncology Group protocol 0212 was used as a reference of potential efficacy. Development of intracranial metastases was recorded. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. RESULTS: Eight men and 12 women with a median age of 61 years enrolled. Two-year overall survival was 88% (95% confidence interval 68%-100%). There was no significant decline in performance between baseline and 6 or 12 months for any of the tests. The association between baseline intelligence quotient and change in performance on testing was not significant. Magnetic resonance imaging revealed asymptomatic brain metastases at a cumulative rate of 20%, with no concurrent extracranial progression. Two patients developed a metastasis in the under-dosed region. Neither involved the dentate gyrus, but 1 involved the avoidance region. Both patients concurrently developed additional metastasis in fully treated brain regions. There were 2 neurologic deaths. CONCLUSIONS: This prospective study suggests a potential benefit of hippocampal sparing in limiting the neuropsychological sequelae of brain radiation, but with a risk of failures in the spared region. These data strongly support continued enrollment on ongoing cooperative group randomized trials. Clinical Trials registration number: NCT01797159.