Effects of the ACTIVity And TEchnology (ACTIVATE) intervention on health-related quality of life and fatigue outcomes in breast cancer survivors.

BACKGROUND: The ACTIVATE Trial examined the efficacy of a wearable-based intervention to increase physical activity and reduce sedentary behavior in breast cancer survivors. This paper examines the effects of the intervention on health-related quality of life (HRQoL) and fatigue at 12 weeks (T2; end of intervention) and 24 weeks (T3; follow-up). METHODS: Inactive and postmenopausal women who had completed primary treatment for stage I-III breast cancer were randomized to intervention or waitlist control. Physical activity and sedentary behavior were measured by Actigraph and activPAL accelerometers at baseline (T1), end of the intervention (T2), and 12 weeks follow-up (T3). HRQoL and fatigue were measured using the Functional Assessment of Cancer Therapy-Breast (FACT-B) and the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue). Primary intervention effects were evaluated comparing intervention and waitlist group at T2 using repeated measures mixed effects models. RESULTS: Overall, 83 women were randomized and trial retention was high (94%). A 4.6-point difference in fatigue score was observed between groups at T2 (95% CI: 1.3, 7.8) indicating improvement in fatigue profiles in the intervention group. In within groups analyses, the intervention group reported a 5.1-point increase in fatigue from baseline to T2 (95% CI: 2.0, 8.2) and a 3.3-point increase from baseline to T3 (95% CI: 0.1, 6.41). CONCLUSIONS: Despite small improvements in fatigue profiles, no effects on HRQoL were observed. While the ACTIVATE Trial was associated with improvements in physical activity and sedentary behavior, more intensive or longer duration interventions may be needed to facilitate changes in HRQoL.

Restorative Narratives for Health Promotion.

Stories may provide a useful way of communicating about health and promoting engagement for health promotion campaigns. In this study, we examined the effectiveness of a particular type of narrative, restorative narratives (stories that highlight hope and resilience), relative to negative narratives (stories that focus on suffering or challenges). We also tested the effect of labeling the story as fact or fiction. The results suggested that restorative narratives may foster greater prosocial behavior than negative narratives and effectiveness does not differ depending on whether a story is labeled as "factual" or "fictional." Our findings offer encouraging implications for future promotional efforts by health organizations.

Maintenance of physical activity and sedentary behavior change, and physical activity and sedentary behavior change after an abridged intervention: Secondary outcomes from the ACTIVATE Trial.

BACKGROUND: This brief report examines the maintenance of moderate to vigorous physical activity (MVPA) and sedentary behavior changes approximately 12 weeks after the delivery of the ACTIVATE Trial primary intervention (use of the Garmin Vivofit 2 activity tracker coupled with a behavioral feedback and goal-setting session and 5 telephone-delivered health coaching sessions). We also examine the efficacy of an abridged intervention (use of the Garmin Vivofit 2 only) in the waitlist control group. METHODS: A pre-post design was employed to examine the secondary aims of the ACTIVATE Trial (n = 80; mean age = 62 years). MVPA and sedentary behavior were measured using Actigraph and activPAL accelerometers after delivery of the primary intervention (T2), and again 12 weeks later (T3). Linear mixed models with random effects were used to examine within-group changes in MVPA and sitting time variables. RESULTS: After the 12-week follow-up period, women in the primary intervention group had maintained their higher levels of MVPA (change from T2 to T3 = 14 min/wk; 95% CI = -18 to 46; P = .37). However, their sitting time increased slightly, by 7 min/d (95% CI = -20 to 34; P = .58), but it did not return to its preintervention level. After receiving the Garmin Vivofit 2, the waitlist control group increased their MVPA by 33 min/wk (95% CI = 3-64; P = .03) and reduced their sitting time by 38 min/d (95% CI = -69 to -7; P = .02) over the same 12-week period. CONCLUSION: The secondary outcomes from the ACTIVATE Trial suggest that wearable technology may generate sustainable changes in MVPA and sitting time. Wearable technology alone may be sufficient to change behavior, at least in the short term.

A randomized controlled trial of a wearable technology-based intervention for increasing moderate to vigorous physical activity and reducing sedentary behavior in breast cancer survivors: The ACTIVATE Trial.

BACKGROUND: The benefits of an active lifestyle after a breast cancer diagnosis are well recognized, but the majority of survivors are insufficiently active. The ACTIVATE Trial examined the efficacy of an intervention (use of the Garmin Vivofit 2 activity monitor coupled with a behavioral feedback and goal-setting session and 5 telephone-delivered health coaching sessions) to increase moderate to vigorous physical activity (MVPA) and reduce sedentary behavior in breast cancer survivors. METHODS: This randomized controlled trial recruited 83 inactive, postmenopausal women diagnosed with stage I-III breast cancer who had completed primary treatment. Participants were randomly assigned to the intervention group or to the control group, and the intervention was delivered over a 12-week period. MVPA and sedentary behavior were measured with Actigraph and activPAL accelerometers at baseline (T1) and at the end of the intervention (T2). RESULTS: Retention in the trial was high, with 80 (96%) of participants completing T2 data collection. At T2, there was a significant between-group difference in MVPA (69 min/wk; 95% CI = 22-116) favoring the intervention group. The trial resulted in a statistically significant decrease in both total sitting time and prolonged bouts (≥20 min) of sitting, with between-group reductions of 37 min/d (95% CI = -72 to -2) and 42 min/d (95% CI = -83 to -2), respectively, favoring the intervention group. CONCLUSION: Results from the ACTIVATE Trial suggest that the use of wearable technology presents an inexpensive and scalable opportunity to facilitate more active lifestyles for cancer survivors. Whether or not such wearable technology-based interventions can create sustainable behavioral change should be the subject of future research.

A qualitative evaluation of breast cancer survivors' acceptance of and preferences for consumer wearable technology activity trackers.

BACKGROUND: Physical inactivity and sedentary behaviour are common amongst breast cancer survivors. These behaviours are associated with an increased risk of comorbidities such as heart disease, diabetes and other cancers. Commercially available, wearable activity trackers (WATs) have potential utility as behavioural interventions to increase physical activity and reduce sedentary behaviour within this population. PURPOSE: The purpose of the study is to explore the acceptability and usability of consumer WAT amongst postmenopausal breast cancer survivors. METHODS: Fourteen participants tested two to three randomly assigned trackers from six available models (Fitbit One, Jawbone Up 24, Garmin Vivofit 2, Garmin Vivosmart, Garmin Vivoactive and Polar A300). Participants wore each device for 2 weeks, followed by a 1-week washout period before wearing the next device. Four focus groups employing a semi-structured interview guide explored user perceptions and experiences. We used a thematic analysis approach to analyse focus group transcripts. RESULTS: Five themes emerged from our data: (1) trackers' increased self-awareness and motivation, (2) breast cancer survivors' confidence and comfort with wearable technology, (3) preferred and disliked features of WAT, (4) concerns related to the disease and (5) peer support and doctor monitoring were possible strategies for WAT application. CONCLUSIONS: WATs are perceived as useful and acceptable interventions by postmenopausal breast cancer survivors. Effective WAT interventions may benefit from taking advantage of the simple features of the trackers paired with other behavioural change techniques, such as specialist counselling, doctor monitoring and peer support, along with simple manual instructions.

Estimating cancers attributable to physical inactivity in Australia.

OBJECTIVES: It was previously estimated that 1814 (1.6 % of incident cancers) were attributable to physical inactivity in Australia in 2010, when only three sites were considered. We estimated the burden of cancer due to physical inactivity in Australia for 13 sites. DESIGN: The population attributable fraction estimated site-specific cancer cases attributable to physical inactivity for 13 cancers. The potential impact fraction was used to estimate cancers that could have been prevented in 2015 if Australian adults had increased their physical activity by a modest amount in 2004-05. METHODS: We used 2004-05 national physical activity prevalence data, 2015 national cancer incidence data, and contemporary relative-risk estimates for physical inactivity and cancer. We assumed a 10-year latency period. RESULTS: An estimated 6361 of the cancers observed in 2015 were attributable to physical inactivity, representing 4.8 % of all cancers diagnosed. If Australian adults had increased their physical activity by one category in 2004-05, 2564 cases (1.9 % of all cancers) could have been prevented in 2015. CONCLUSIONS: More than three times as many cancers are attributable to physical inactivity than previously reported. Physical activity promotion should be a central component of cancer prevention programmes in Australia.

Linking Physical Activity to Breast Cancer Risk via Inflammation, Part 1: The Effect of Physical Activity on Inflammation.

The protective effect of physical activity on breast cancer incidence may partially be mediated by inflammation. Systematic searches of Medline, EMBASE, and SPORTDiscus were performed to identify intervention studies, Mendelian randomization studies, and prospective cohort studies that examined the effects of physical activity on circulating inflammatory biomarkers in adult women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the Grading of Recommendations Assessment, Development, and Evaluation system was used to determine the overall quality of the evidence. Thirty-five intervention studies and one observational study met the criteria for inclusion. Meta-analyses of randomized controlled trials (RCT) indicated that, compared with control groups, exercise interventions reduced levels of C-reactive protein (CRP) [standardized mean difference (SMD) = -0.27, 95% confidence interval (CI) = -0.62 to 0.08), tumor necrosis factor alpha (TNFα, SMD = -0.63, 95% CI = -1.04 to -0.22), interleukin-6 (IL6, SMD = -0.55, 95% CI = -0.97 to -0.13) and leptin (SMD = -0.50, 95% CI = -1.10 to 0.09). Owing to heterogeneity in effect estimates and imprecision, evidence strength was graded as low (CRP, leptin) or moderate (TNFα and IL6). High-quality evidence indicated that exercise did not change adiponectin levels (SMD = 0.01, 95% CI = -0.14 to 0.17). These findings provide support for the biological plausibility of the first part of the physical activity-inflammation-breast cancer pathway.

Linking Physical Activity to Breast Cancer via Inflammation, Part 2: The Effect of Inflammation on Breast Cancer Risk.

This review synthesized and appraised the evidence for an effect of inflammation on breast cancer risk. Systematic searches identified prospective cohort and Mendelian randomization studies relevant to this review. Meta-analysis of 13 biomarkers of inflammation were conducted to appraise the evidence for an effect breast cancer risk; we examined the dose-response of these associations. Risk of bias was evaluated using the ROBINS-E tool and the quality of evidence was appraised with Grading of Recommendations Assessment, Development, and Evaluation. Thirty-four observational studies and three Mendelian randomization studies were included. Meta-analysis suggested that women with the highest levels of C-reactive protein (CRP) had a higher risk of developing breast cancer [risk ratio (RR) = 1.13; 95% confidence interval (CI), 1.01-1.26] compared with women with the lowest levels. Women with highest levels of adipokines, particularly adiponectin (RR = 0.76; 95% CI, 0.61-0.91) had a reduced breast cancer risk, although this finding was not supported by Mendelian randomization analysis. There was little evidence of an effect of cytokines, including TNFα and IL6, on breast cancer risk. The quality of evidence for each biomarker ranged from very low to moderate. Beyond CRP, the published data do not clearly support the role of inflammation in the development of breast cancer.

Linking Physical Activity to Breast Cancer: Text Mining Results and a Protocol for Systematically Reviewing Three Potential Mechanistic Pathways.

Epidemiologic research suggests that physical activity is associated with a reduced risk of breast cancer, but the causal nature of this link is not clear. Investigating mechanistic pathways can provide evidence of biological plausibility and improve causal inference. This project will examine three putative pathways (sex steroid hormones, insulin signaling, and inflammation) in a series of two-stage systematic reviews. Stage 1 used Text Mining for Mechanism Prioritisation (TeMMPo) to identify and prioritize relevant biological intermediates. Stage 2 will systematically review the findings from studies of (i) physical activity and intermediates and (ii) intermediates and breast cancer. Ovid MEDLINE, EMBASE, and SPORTDiscus will be searched using a combination of subject headings and free-text terms. Human intervention and prospective, observational studies will be eligible for inclusion. Meta-analysis will be performed where possible. Risk of bias will be assessed using the Cochrane Collaboration tool, or the ROBINS-I or ROBINS-E tool, depending on study type. Strength of evidence will be assessed using the GRADE system. In addition to synthesizing the mechanistic evidence that links physical activity with breast cancer risk, this project may also identify priority areas for future research and help inform the design and implementation of physical activity interventions.See related reviews by Swain et al., p. 16 and Drummond et al., p. 28.

Linking Physical Activity to Breast Cancer Risk via the Insulin/Insulin-like Growth Factor Signaling System, Part 2: The Effect of Insulin/Insulin-like Growth Factor Signaling on Breast Cancer Risk.

Perturbation of the insulin/insulin-like growth factor (IGF) signaling system is often cited as a mechanism driving breast cancer risk. A systematic review identified prospective cohort studies and Mendelian randomization studies that examined the effects of insulin/IGF signaling (IGF, their binding proteins (IGFBP), and markers of insulin resistance] on breast cancer risk. Meta-analyses generated effect estimates; risk of bias was assessed and the Grading of Recommendations Assessment, Development and Evaluation system applied to evaluate the overall quality of the evidence. Four Mendelian randomization and 19 prospective cohort studies met our inclusion criteria. Meta-analysis of cohort studies confirmed that higher IGF-1 increased risk of breast cancer; this finding was supported by the Mendelian randomization studies. IGFBP-3 did not affect breast cancer. Meta analyses for connecting-peptide and fasting insulin showed small risk increases, but confidence intervals were wide and crossed the null. The quality of evidence obtained ranged from 'very low' to 'moderate'. There were insufficient studies to examine other markers of insulin/IGF signaling. These findings do not strongly support the biological plausibility of the second part of the physical activity-insulin/IGF signaling system-breast cancer pathway. Robust conclusions cannot be drawn due to the dearth of high quality studies. See related article by Swain et al., p. 2106.

Linking Physical Activity to Breast Cancer Risk via Insulin/Insulin-Like Growth Factor Signaling System, Part 1: The Effect of Physical Activity on the Insulin/Insulin-Like Growth Factor Signaling System.

Physical activity may reduce the risk of developing breast cancer via its effect on the insulin/insulin-like growth factor (IGF) signaling system. A systematic review searched for randomized controlled trials (RCT), Mendelian randomization and prospective cohort studies that examined the effects of physical activity on insulin/IGF signaling [IGFs, their binding proteins (IGFBP), and markers of insulin resistance] in adult women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the Grading of Recommendations Assessment, Development, and Evaluation system used to determine the overall quality of the evidence. Fifty-eight RCTs met our inclusion criteria, no observational or Mendelian randomization studies met the criteria for inclusion. Meta-analyses indicated that physical activity interventions (vs. control) reduced fasting insulin, the Homeostatic Model Assessment for Insulin Resistance and fasting glucose. Physical activity increased IGF-1, but there was no clear effect on IGFBP-3 or the ratio of IGF-1:IGFBP-3. Strong evidence was only established for fasting insulin and insulin resistance. Further research is needed to examine the effect of physical activity on C-peptide and HBA1c in women. Reductions in fasting insulin and insulin resistance following exercise suggest some biological plausibility of the first part of the physical activity-insulin/IGF signaling-breast cancer pathway. See related article by Drummond et al., p. 2116.

Linking Physical Activity to Breast Cancer via Sex Hormones, Part 1: The Effect of Physical Activity on Sex Steroid Hormones.

The effect of physical activity on breast cancer risk may be partly mediated by sex steroid hormones. This review synthesized and appraised the evidence for an effect of physical activity on sex steroid hormones. Systematic searches were performed using MEDLINE (Ovid), EMBASE (Ovid), and SPORTDiscus to identify experimental studies and prospective cohort studies that examined physical activity and estrogens, progestins, and/or androgens, as well as sex hormone binding globulin (SHBG) and glucocorticoids in pre- and postmenopausal women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the GRADE system was used to appraise quality of the evidence. Twenty-eight randomized controlled trials (RCT), 81 nonrandomized interventions, and six observational studies were included. Estrogens, progesterone, and androgens mostly decreased, and SHBG increased, in response to physical activity. Effect sizes were small, and evidence quality was graded moderate or high for each outcome. Reductions in select sex steroid hormones following exercise supports the biological plausibility of the first part of the physical activity-sex hormone-breast cancer pathway. The confirmed effect of physical activity on decreasing circulating sex steroid hormones supports its causal role in preventing breast cancer.See related reviews by Lynch et al., p. 11 and Drummond et al., p. 28.

Linking Physical Activity to Breast Cancer via Sex Steroid Hormones, Part 2: The Effect of Sex Steroid Hormones on Breast Cancer Risk.

We undertook a systematic review and appraised the evidence for an effect of circulating sex steroid hormones and sex hormone-binding globulin (SHBG) on breast cancer risk in pre- and postmenopausal women. Systematic searches identified prospective studies relevant to this review. Meta-analyses estimated breast cancer risk for women with the highest compared with the lowest level of sex hormones, and the DRMETA Stata package was used to graphically represent the shape of these associations. The ROBINS-E tool assessed risk of bias, and the GRADE system appraised the strength of evidence. In premenopausal women, there was little evidence that estrogens, progesterone, or SHBG were associated with breast cancer risk, whereas androgens showed a positive association. In postmenopausal women, higher estrogens and androgens were associated with an increase in breast cancer risk, whereas higher SHBG was inversely associated with risk. The strength of the evidence quality ranged from low to high for each hormone. Dose-response relationships between sex steroid hormone concentrations and breast cancer risk were most notable for postmenopausal women. These data support the plausibility of a role for sex steroid hormones in mediating the causal relationship between physical activity and the risk of breast cancer.See related reviews by Lynch et al., p. 11 and Swain et al., p. 16.

Effects of a wearable technology-based physical activity intervention on sleep quality in breast cancer survivors: the ACTIVATE Trial.

INTRODUCTION: Physical activity interventions can improve sleep quality in breast cancer survivors. This paper examines the effects of the ACTIVATE Trial, a wearable-based physical activity intervention (Garmin Vivofit2® coupled with behavioral feedback, goal setting, and health coaching) on sleep outcomes. METHODS: Post-primary treatment, inactive, postmenopausal breast cancer survivors were recruited and randomized to primary intervention or waitlist. Wrist-worn actigraphy (sleep onset latency, SOL; total sleep time, TST; sleep efficiency, SE; wake after sleep onset, WASO; and number of awakenings, NWAKE) and questionnaire-derived sleep measures (Pittsburgh Sleep Quality Index) were assessed at baseline (T1), 12 weeks (end of primary intervention and start of waitlist intervention, T2), and at 24 weeks (T3). RESULTS: Eighty-three women (mean age = 62 years) were randomized; trial retention was 94% at T2 and 87% at T3. At T2, primary intervention participants had greater improvements in WASO (- 5.7 min, 95% CI - 11.7 to - 0.2) and NWAKE compared with the waitlist arm (- 2.0, 95% CI - 3.6 to - 0.4). At T3, within-group improvements were observed for SE (both groups), WASO (both groups), NWAKE (primary intervention group only), total PSQI score (primary intervention group), and sleep efficacy (primary intervention group). CONCLUSIONS: The intervention reduced actigraphy-measured sleep disturbances. Within-group analyses suggest that improvements in sleep quality are sustained over a longer duration, and there may be similar benefits from an abridged intervention (wearable device only). Actigraphy-measured effects appeared stronger in participants who were poor sleepers at study entry. IMPLICATIONS FOR CANCER SURVIVORS: Wearable technology can increase physical activity and improve sleep for breast cancer survivors.

Study design and methods for the ACTIVity And TEchnology (ACTIVATE) trial.

BACKGROUND: Physical activity is positively associated with survival and quality of life among breast cancer survivors. Despite these benefits, the majority of breast cancer survivors are insufficiently active. The potential health benefits of reducing sedentary behaviour (sitting time) in this population have not been extensively investigated. The ACTIVATE Trial will evaluate the efficacy of an intervention that combines wearable technology (the Garmin Vivofit2®) with traditional behavioural change approaches to increase physical activity and reduce sedentary behaviour performed by breast cancer survivors. METHODS/DESIGN: This randomised controlled trial includes inactive, postmenopausal women diagnosed with stage I-III breast cancer who have completed their primary treatment. Participants are randomly assigned to the primary intervention group (Garmin Vivofit2®; behavioural feedback and goal setting session; and, five telephone-delivered health coaching sessions) or to the wait-list control group. The primary intervention is delivered over a 12-week period. The second 12-week period comprises a maintenance phase for the primary intervention group, and an abridged intervention (Garmin Vivofit2® only) for the wait-list control group. Moderate- to vigorous-intensity physical activity (MVPA) and sedentary behaviour are assessed by accelerometry at baseline (T1), end of intervention (T2), and end of maintenance phase (T3). DISCUSSION: The ACTIVATE Trial is one of the first studies to incorporate wearable technology into an intervention for cancer survivors. If the use of wearable technology (in combination with behaviour change strategies, or alone) proves efficacious, it may become an inexpensive and sustainable addition to the health promotion strategies available to health care providers in the cancer survivorship context. TRIAL REGISTRATION: ACTRN12616000175471.

EGFR and KRAS mutations do not enrich for the activation of IL-6, JAK1 or phosphorylated STAT3 in resected lung adenocarcinoma.

Resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) against EGFR mutant lung adenocarcinoma develops after a median of nine to thirteen months. Upregulation of the interleukin-6 (IL-6)/Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway may be a potential source of resistance to EGFR TKIs. We undertook a detailed assessment of the IL-6/JAK1/phosphorylated STAT3 (pSTAT3) pathway in resected lung adenocarcinoma specimens, with special interest in whether the presence of an EGFR mutation enriched for pSTAT3 positivity. Tumours from 143 patients with resected lung adenocarcinoma were assessed. EGFR and KRAS mutation status were scanned for with high-resolution melting and confirmed by polymerase chain reaction. Immunohistochemisty (IHC) was performed for IL-6, gp130, JAK1 and pSTAT3. Two methods for assigning IHC positivity were assessed (the presence of any positivity, and the presence of positivity at an H score >40). We found statistically significant associations between IL-6, JAK1 and pSTAT3 measured by IHC, consistent with the activation of the pathway in clinical specimens. No relationship was demonstrated between members of this pathway and oncogenic mutations in EGFR or KRAS. However, a proportion of tumours with EGFR mutations showed staining for IL-6, JAK1 and pSTAT3. No correlations with clinicopathologic features or survival outcomes were found for IL-6, JAK1 or pSTAT3 staining. The presence of EGFR or KRAS mutations did not enrich for the activation of IL-6, JAK1 or pSTAT3. pSTAT3 may still play a role in resistance to EGFR TKIs in clinical practice.

EGFR gene copy number alterations are not a useful screening tool for predicting EGFR mutation status in lung adenocarcinoma.

We investigated if gene copy number (GCN) alterations of the epidermal growth factor receptor (EGFR), as detected by silver enhanced in situ hybridisation (SISH), could be used to select patients for EGFR mutation testing. Resected lung adenocarcinoma specimens with adequate tumour were identified. EGFR SISH was performed using the Ventana Benchmark Ultra platform. EGFR GCN was classified according to the Colorado Classification System. EGFR mutations were scanned by high resolution melting and confirmed by Sanger sequencing. Thirty-four of 96 tumours were EGFR SISH positive (35%), and 31 of 96 tumours harboured one or more EGFR mutations (32%). Of 31 EGFR-mutant tumours, 18 were EGFR SISH positive (58%). There was a statistically significant relationship between the presence of an EGFR mutation and EGFR GCN (p = 0.003). Thirteen of 31 EGFR-mutant tumours were EGFR SISH negative (42%), and 16 of 65 EGFR-wild type tumours were EGFR SISH positive (24%). The sensitivity, specificity, positive predictive value and negative predictive value were 58%, 75%, 52.9% and 79%, respectively. Despite a significant relationship between EGFR GCN alterations and EGFR mutations, our results indicate that EGFR GCN as detected by SISH is not a suitable way to select patients for EGFR mutation testing.

The clinical relevance of pathologic subtypes in metastatic lung adenocarcinoma.

INTRODUCTION: The International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification of lung adenocarcinoma recommends identification of pathologic patterns in metastatic samples where possible. We investigated the clinical relevance of these patterns. METHODS: Patients with a surgical biopsy of lung adenocarcinoma from a metastatic site were included. Slides were reviewed by an anatomical pathologist identifying the histologic patterns of solid with mucin, acinar, micropapillary, papillary, and assigning a major adenocarcinoma subtype according to the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. EGFR and KRAS mutation testing were performed on formalin-fixed, paraffin-embedded blocks. Mutations were detected by high resolution melting assay with high resolution melting-positive samples confirmed by Sanger sequencing. RESULTS: One-hundred patients were included. The major histologic subtype prevalence was as follows: solid (50), acinar (29), micropapillary (20), and papillary (1). Of 100 patients, 45 received no systemic therapy with no overall survival differences seen by histologic subtype and 55 received systemic therapy (chemoradiotherapy with curative intent or palliative chemotherapy). Worse survival was seen in the major solid histologic subtype compared with major acinar (hazard ratio 0.32 [95% confidence interval 0.15-0.68], p = 0.003) and micropapillary subtypes (hazard ratio 0.34 [95% confidence interval, 0.17-0.69], p = 0.003). The major solid histologic subtype was less likely to harbor EGFR mutations (p = 0.006) and was less frequent in never smokers (p = 0.010) compared with other histologic subtypes. CONCLUSION: The major solid histologic subtype of lung adenocarcinoma at metastatic sites is associated with shorter overall survival on systemic anticancer therapy. Furthermore, the major solid histologic subtype is less likely to harbor EGFR mutations. These results require validation in larger cohorts.