Different efficacy of CT screening for lung cancer according to histological type: analysis of Japanese-smoker cases detected using a low-dose CT screen

Sublobar resections for lung cancer: Finally, some answers and some more questions?

The Lung Cancer Study Group Trial, published in 1995, set the tone for lobectomy as the standard of care for early-stage nonsmall cell lung cancer. Twenty-seven years and two randomized trials later, does the thoracic oncology community have clarity regarding the choice type of resection, or more questions?

Small Cell Lung Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Small Cell Lung Cancer (SCLC) provide recommended management for patients with SCLC, including diagnosis, primary treatment, surveillance for relapse, and subsequent treatment. This selection for the journal focuses on metastatic (known as extensive-stage) SCLC, which is more common than limited-stage SCLC. Systemic therapy alone can palliate symptoms and prolong survival in most patients with extensive-stage disease. Smoking cessation counseling and intervention should be strongly promoted in patients with SCLC and other high-grade neuroendocrine carcinomas. The "Summary of the Guidelines Updates" section in the SCLC algorithm outlines the most recent revisions for the 2022 update, which are described in greater detail in this revised Discussion text.

Community-based lung cancer screening by low-dose computed tomography in China: First round results and a meta-analysis

OBJECTIVE

To evaluate the efficiency of low-dose computed tomography (LDCT) screening for lung cancer in China by analyzing the baseline results of a community-based screening study accompanied with a meta-analysis.

METHODS

A first round of community-based lung cancer screening with LDCT was conducted in Tianjin, China, and a systematic literature search was performed to identify LDCT screening and registry-based clinical studies for lung cancer in China. Baseline results in the community-based screening study were described by participant risk level and the lung cancer detection rate was compared with the pooled rate among the screening studies. The percentage of patients per stage was compared between the community-based study and screening and clinical studies.

RESULTS

In the community-based study, 5523 participants (43.6% men) underwent LDCT. The lung cancer detection rate was 0.5% (high-risk, 1.2%; low-risk, 0.4%), with stage I disease present in 70.0% (high-risk, 50.0%; low-risk, 83.3%), and the adenocarcinoma present in 84.4% (high-risk, 61.5%; low-risk, 100%). Among all screen-detected lung cancer, women accounted for 8.3% and 66.7% in the high- and low-risk group, respectively. In the screening studies from mainland China, the lung cancer detection rate 0.6% (95 %CI: 0.3%-0.9%) for high-risk populations. The proportions with carcinoma in situ and stage I disease in the screening and clinical studies were 76.4% (95 %CI: 66.3%-85.3%) and 15.2% (95 %CI: 11.8%-18.9%), respectively.

CONCLUSIONS

The stage shift of lung cancer due to screening suggests a potential effectiveness of LDCT screening in China. Nearly 70% of screen-detected lung cancers in low-risk populations are identified in women.

Preoperative Watchful-Waiting Time and Surgical Outcome of Patients with Non-small Cell Lung Cancer Found by Chest Low-Dose CT Screening

BACKGROUNDS

Chest low-dose CT screening (LDCTS) has been finding unprecedented numbers of peripheral non-small cell lung cancers (NSCLC) at an early stage and increased the number of patients with surgical indication. It is important to explore the influence of preoperative watchful-waiting time (WWT) on surgical outcomes. Objective is to clarify relationship between WWT and surgical outcomes of LDCTS-finding NSCLC from the view point of treatment delay.

METHODS

Total 283 cases of NSCLC, found by LDCTS and consecutively resected, were surveyed for preoperative WWT and surgical outcomes. Validity of the present guideline for management of pulmonary nodules detected by LDCTS was verified whether WWT before surgery was suitable for eradication of NSCLC.

RESULTS

The median value of WWT was 4.0 months in total, and the distribution of WWT exhibited long-tail-type pattern. That was 5.0 months in the group of pure ground-glass nodule (pGGN), 4.0 months in the group of part-solid nodule (PSN), and 1.7 months in the group of solid nodule (SON). During long-term postoperative observation time (median 79 months), 10-year progression-free survival rates were 100% in pGGN, 96% in PSN, and 72% in SON (P < .0001). They decreased significantly depending on enlargement of size: 91% or higher in size of 2 cm or smaller, and 71% or lower in size of larger than 2 cm (P < .0001).

CONCLUSIONS

Limited to LDCTS-finding nodules, surgical outcome will depend mainly on some malignant potential of NSCLC per se, rather than on duration of WWT or treatment delay.

Characteristics and Outcomes of Small Cell Lung Cancer Detected by CT Screening

BACKGROUND

Previous studies with a limited number of patients have reported divergent findings on whether screening can detect small cell lung cancer (SCLC) at an earlier stage and whether there might be a survival benefit.

METHODS

This study examined the characteristics of SCLC detected by using low-dose CT (LDCT) screening in the National Lung Screening Trial, a randomized study of individuals at high risk for developing lung cancer comparing LDCT imaging vs chest radiography. SCLC was denoted as screen detected if diagnosed ≤ 1 year of a positive screen or after a longer period but with no time gap between diagnostic procedures of > 1 year; interval detected if diagnosed ≤ 1 year of a negative screen; and nonscreen detected if the subject did not receive any screens or otherwise as postscreening.

RESULTS

A total of 143 cases of SCLC were diagnosed, including 49 (34.2%) screen detected, 15 (10.5%) interval detected, and 79 (55.2%) nonscreened/postscreening. Of the screening phase-diagnosed cases (ie, screen or interval detected), a higher proportion of SCLC cases compared with NSCLC cases were interval detected (23% vs 5%; P < .0001). A higher proportion of all SCLC cases compared with NSCLC cases were advanced stage (III/IV: 86% vs 36%; P < .0001). The unfavorable SCLC stage distribution extended across screen-detected (80% stage III/IV), interval-detected (86%), and nonscreened/postscreening (90%) cancers. Among screen-detected SCLC, only 63.3% had ≥ 1 noncalcified nodule in the cancer lobe compared with 85.4% of NSCLC cases (P < .0001). Even with very small LDCT screen-detected nodules, a high proportion of SCLC cases were late stage. There was no significant difference in survival between screen- and interval-detected or postscreening SCLC.

CONCLUSIONS

"Early detection" with the use of LDCT imaging had no impact on SCLC outcomes. A successful screening modality should ideally detect SCLC earlier than when it can be detected on LDCT scans.

Differences in Patient Outcomes of Prevalence, Interval, and Screen-Detected Lung Cancers in the CT Arm of the National Lung Screening Trial

Lung cancer screening identifies cancers with heterogeneous behaviors. Some lung cancers will be identified among patients who had prior negative CT screens and upon follow-up scans develop a de novo nodule that was determined to be cancerous. Other lung cancers will be identified among patients who had one or more prior stable positive scans that were not determined to be lung cancer (indeterminate pulmonary nodules), but in follow-up scans was diagnosed with an incidence lung cancer. Using data from the CT arm of the National Lung Screening Trial, this analysis investigated differences in patient characteristics and survival endpoints between prevalence-, interval-, and screen-detected lung cancers, characterized based on sequence of screening results. Lung cancers immediately following a positive baseline (T0), and prior to the T1 screen, formed the prevalence cohort. Interval cancers were diagnosed following a negative screen at any time point prior to the next screening round. Two cohorts of screen-detected lung cancers (SDLC) were identified that had a baseline positive screen that was that was not determined to be lung cancer (i.e., an indeterminate pulmonary nodule), but in follow-up scans was diagnosed with an incidence lung cancer 12 (SDLC1) or 24 (SDLC2) months later. Two other incidence cohorts had screen-detected lung cancers that had baseline negative screen and upon follow-up scans developed a de novo nodule determined to be cancerous at 12 (SDLC3) or 24 (SDLC4) months later. Differences in patient characteristics, progression-free survival (PFS), and overall survival (OS) were assessed. The lung cancer-specific death rate was higher for SDLC3/SDLC4 compared to SDLC1/SDLC2 lung cancers (136.6/1,000 person-years vs. 71.3/1,000 person-years, P < 0.001). Moreover, PFS and OS were significantly lower for SDLC3/SDLC4 compared to SDLC1/SDLC2 (P < 0.004; P < 0.002, respectively). The findings were consistent when stratified by stage and histology. Multivariable Cox proportional models revealed that the SDLC3/SDLC4 case groups were associated with significantly poorer PFS (HR = 1.89; 95% CI 1.31-2.74) and OS (HR = 1.80; 95% CI 1.21-2.67) compared to SDLC1/SDLC2 lung cancers (HR = 1.00). Lung cancer patients who develop a de novo nodule that determined to be cancerous (i.e., at least one negative CT screen prior to cancer diagnosis) had poorer survival outcomes compared to patients who had at least one positive screen prior to cancer diagnosis. As such, the observation that de novo screen-detected are associated with poorer survival could be attributed to faster growing, more aggressive cancers that arose from a lung environment previously lacking focal abnormalities.

Clinical outcomes in patients with small cell lung cancer in a single institute: Comparative analysis of radiographic screening with symptom-prompted patients

OBJECTIVES

The present study was performed to evaluate the differences in clinical characteristics and survival outcomes of patients with small cell lung cancer (SCLC) according to methods used for detecting the disease: radiographic screening or symptomatically prompted.

MATERIALS AND METHODS

The clinical findings and actual treatment outcomes were estimated according to three means of detection of SCLC: computed tomography (CT), radiographic test, and symptom-prompted cases.

RESULTS

We identified 147 patients (male/female ratio: 127/20; mean age: 68.1 years old) between 2000 and 2011. The patients were divided into three categories according to method of detection: chest CT (CT; n=24), radiographic screening (CXR; n=37), and symptom-prompted cases (symptom; n=86). There was no significant shift to early TNM stage distribution in the CT or CXR group compared with the symptom group. However, the rates of limited disease (LD)-SCLC were significantly higher in the CT and CXR groups than the symptom group. Median survival times were 17.0 months (95% confidence interval (CI): 11.6-22.4) in the CT group, 19.0 months (95%CI: 11.7-126.3) in the CXR group, and 12.0 months (95%CI: 9.6-14.4) in the symptom group. There were statistically significant differences in overall survival between CT and symptom groups (P<0.05) and between CXR and symptom groups (P<0.001). However, there was no significant difference in survival between CT and CXR groups.

CONCLUSIONS

Radiographic (CT plus CXR) testing contributes to better clinical outcome in patients with SCLC.

Tumor size and computed tomography attenuation of pulmonary pure ground-glass nodules are useful for predicting pathological invasiveness

Objectives

Pulmonary ground-glass nodules (GGNs) are occasionally diagnosed as invasive adenocarcinomas. This study aimed to evaluate the clinicopathological features of patients with pulmonary GGNs to identify factors predictive of pathological invasion.

Methods

We retrospectively evaluated 101 pulmonary GGNs resected between July 2006 and November 2013 and pathologically classified them as adenocarcinoma in situ (AIS; n = 47), minimally invasive adenocarcinoma (MIA; n = 30), or invasive adenocarcinoma (I-ADC; n = 24). The age, sex, smoking history, tumor size, and computed tomography (CT) attenuation of the 3 groups were compared. Receiver operating characteristic (ROC) curve analyses were performed to identify factors that could predict the presence of pathologically invasive adenocarcinomas.

Results

Tumor size was significantly larger in the MIA and I-ADC groups than in the AIS group. CT attenuation was significantly greater in the I-ADC group than in the AIS and MIA groups. In ROC curve analyses, the sensitivity and specificity of tumor size (cutoff, 11 mm) were 95.8% and 46.8%, respectively, and those for CT attenuation (cutoff, −680 HU) were 95.8% and 35.1%, respectively; the areas under the curve (AUC) were 0.75 and 0.77, respectively. A combination of tumor size and CT attenuation (cutoffs of 11 mm and −680 HU for tumor size and CT attenuation, respectively) yielded in a sensitivity and specificity of 91.7% and 71.4%, respectively, with an AUC of 0.82.

Conclusions

Tumor size and CT attenuation were predictive factors of pathological invasiveness for pulmonary GGNs. Use of a combination of tumor size and CT attenuation facilitated more accurate prediction of invasive adenocarcinoma than the use of these factors independently.

Differences in clinical presentation of non-small cell lung cancer in never-smokers versus smokers

OBJECTIVES

This study was conducted to evaluate whether or not tumor spread and the diagnostic process in non-small cell lung cancer (NSCLC) is different based on smoking history.

METHODS

Associations between smoking status and clinical presentation were evaluated controlling for the effect of histology. Lung cancer with delayed diagnosis (LCDD) and incidental detection (LCID) were determined based on medical records.

RESULTS

Of 914 patients, frequency of distant metastases was more common in never-smokers than in smokers (59% and 36%, respectively; P<0.001). Although never-smokers were more likely to have LCDD than smokers (18% and 11%, respectively; P=0.038), LCDD were not significantly associated with frequency of distant metastases [49% (LCDD) vs. 42% (non-LCDD); P=0.189] as well as tumor [29% (T3-4) vs. 24% (T1-2); P=0.134] and node [43% (N2-3) vs. 44% (N0-1); P=0.838] stage. Interestingly, never-smokers are more likely to have LCID than smokers (31% and 19%, respectively; P=0.010). In survival analysis, LCID (P=0.001; HR, 0.63) remained a prognostic factor, while LCDD did not.

CONCLUSIONS

This study suggests distinct metastatic pattern and diagnostic processes of never-smokers. The link between survival and incidental detection was also indicated.

The National Lung Screening Trial: results stratified by demographics, smoking history, and lung cancer histology

BACKGROUND

The National Lung Screening Trial (NLST), which compared lung cancer screening with low-dose computed tomography (LDCT) versus chest radiography (CXR), demonstrated a statistically significant mortality benefit of LDCT screening. In the current study, the authors performed a post hoc analysis to examine whether the benefit was affected by various baseline factors, including age, sex, and smoking status, and whether it differed by tumor histology.

METHODS

Lung cancer death rates were computed as events over person-years of observation; the mortality risk ratio (RR) was defined as the lung cancer death rate in the LDCT versus CXR trial arms. Poisson regression was used to test for interactions of sex, age (< 65 years vs ≥ 65 years), and smoking status (current vs former) with trial arm. Mortality RRs were also computed for specific lung cancer histologies.

RESULTS

The overall mortality RR was 0.92 in men and 0.73 in women, with a P value for interaction of .08. RRs were similar for individuals aged < 65 years versus those aged ≥ 65 years (0.82 vs 0.87), and for current versus former smokers (0.81 vs 0.91). By tumor histology, mortality RRs were 0.75 for adenocarcinoma, 0.71 for all non-small cell lung cancers except squamous, 1.23 for squamous cell carcinoma, and 0.90 for small cell carcinoma. RRs were similar for men and women for nonsquamous non-small cell lung cancers (0.71 and 0.70, respectively); women were found to have lower RRs for small cell and squamous cell carcinoma.

CONCLUSIONS

A benefit of LDCT did not appear to vary substantially by age or smoking status; there was weak evidence of a differential benefit by sex. A differential benefit across lung cancer histologies may exist.

Clinical characteristics and outcomes of patients with small cell lung cancer detected by CT screening

The present study was performed to evaluate the clinical characteristics and survival outcomes in patients with small cell lung cancer (SCLC) detected by low-dose computed tomography (CT). We retrospectively reviewed clinical records of patients with SCLC treated at our hospital between 1997 and 2011 and selected patients with SCLC detected by CT screening. We identified 12 patients (male/female 11/1; mean age 67.8 years old. Nine patients had limited disease (LD), and 3 had extensive disease (ED). Five LD patients underwent thoracic surgery, and the pathological staging information included stage IA (n = 1), IB (n = 1), IIA (n = 1), and IIIB (n = 2). Although 2 patients with pathological stages IA and IB had >10-year survival, the median survival times (MST) in LD and ED were 25 months (95 % CI 17.0-32.9) and 16 months (95 % CI; not evaluated), respectively. In addition, MST in 12 patients was not significantly different from that in SCLC patients in general care in our hospital. This analysis suggested that CT screening contributes to the detection of early-stage SCLC in patients that are potentially suitable for surgery, but it remains unclear how to improve clinical outcome in patients with SCLC.

Surgical outcomes in patients with small cell lung cancer: comparative analysis of computed tomograpy-detected patients with others

Background

It is shown that low-dose computed tomography (CT) screening is useful for a reduction in lung-cancer-specific mortality in heavy smokers. However, the information about effectiveness according to the histological types of lung cancer has not been adequately investigated especially small cell lung cancer (SCLC). The present study was performed to see the clinical benefit of CT screening in patients with SCLC following thoracotomy.

Methods

We retrospectively reviewed the outcome in patients with early stage SCLC who initially underwent thoracotomy. The clinical stages and actuarial survival were estimated according to the three means of detection of SCLC: chest CT, radiographic screen, and symptomatically prompted cases.

Results

Sixty-nine patients (men/women, 63/6; mean age, 70 years) with SCLC underwent thoracotomy between 1991 and 2010 including chest CT (n = 13), radiographic screening (n = 39), and symptomatically prompted cases (n = 17). Pathological staging information included stage IA (n = 25), IB (n = 8), IIA (n = 13), IIB (n = 5), IIIA (n = 11), and IIIB (n = 7). Median survival time was 30.0 (95% confidence interval (CI): 22.0 to 57.0) months, with overall survival at 5 years of 34.3% (95% CI, 23.47 to 47.3). Nine patients (69%) with stage I were detected by CT which was significantly higher than those in other detection arms. However, there were no significant differences in the survival between CT and other detection arms.

Conclusions

CT examination may be useful for detection in early stage SCLC potentially suitable for surgery, but the contribution to better clinical outcome in patients with SCLC remains unclear.