Prognostic prediction of clinical stage IA lung cancer presenting as a pure solid nodule

Differential efficacy of segmentectomy and wedge resection in sublobar resection compared to lobectomy for solid-dominant stage IA lung cancer: a systematic review and meta-analysis

BACKGROUND

Currently, the impact of sublobar resection versus lobectomy on the prognosis of solid-dominant stage IA lung cancer is contradictory in different studies, which requires further exploration.

METHODS

The authors analyzed 26 studies, including one randomized controlled trial and retrospective cohort studies. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using fixed-effects or random-effects models based on heterogeneity levels.

RESULTS

The analysis included 12 667 patients, with 3488 undergoing sublobar resections and 9179 receiving lobectomies. The overall analysis revealed no statistically significant difference in overall survival (OS) (HR=1.28, 95% CI: 0.98-1.69) between sublobar resection and lobectomy, but lobectomy was associated with better recurrence-free survival (RFS) (HR=1.39, 95% CI: 1.10-1.75). Subgroup analyses revealed that, for tumors with a diameter ≤2 cm, sublobar resection versus lobectomy showed no significant difference in OS but sublobar resection had lower RFS. For 2-3 cm tumors, both OS and RFS were significantly lower in the sublobar resection group. When consolidation-to-tumor ratio (CTR) ranged from 0.5 to <1, OS did not differ significantly, but RFS was significantly lower in sublobar resection. Lung cancers with CTR=1 showed significantly lower OS and RFS in the sublobar resection group. Segmentectomy provided similar OS and RFS compared to lobectomy, while wedge resection had a detrimental effect on patient prognosis. However, wedge resection may have provided comparable outcomes for patients aged 75 years or older.

CONCLUSION

Our findings suggest that segmentectomy and lobectomy yield similar oncological outcomes. However, compared to lobectomy, wedge resection is associated with a poorer prognosis. Nevertheless, for elderly patients, wedge resection is also a reasonable surgical option.

Segmentectomy versus lobectomy for small-sized pure solid non-small cell lung cancer

BACKGROUND

Segmentectomy has been recommended for ground glass opacity (GGO)-dominant small-sized non-small cell lung cancer (NSCLC) or those with GGO component. Pure solid NSCLC is a special sub-type and has an inferior prognosis. Whether segmentectomy could achieve comparable long-term outcomes with lobectomy for pure solid small-sized NSCLC remained controversial. This study aimed to compare the prognosis of segmentectomy and lobectomy for pure solid NSCLC.

METHODS

NSCLC patients with a pure solid nodule (≤2 cm) who received segmentectomy or lobectomy between January 2010 and June 2019 were retrospectively screened. Log-rank test, univariable, and multivariable Cox regression analyses were used for prognostic comparison. Further, the propensity score matching analysis was adopted to yield a matched cohort.

RESULTS

After screening, 344 pure solid NSCLC patients with a median follow-up time of 56 months were reserved. Among them, 98 patients underwent segmentectomy and the other 246 subjects received lobectomy. The lobectomy group had a larger tumor size, a higher rate of lymph node metastasis than the segmentectomy arm. Generally, patients with segmentectomy had a better disease-free survival (DFS) (p = 0.011) and overall survival (OS) (p = 0.028) than those with lobectomy. However, the multivariable Cox regression analysis indicated that no significant survival difference existed between segmentectomy and lobectomy after adjusting the potential confounding factors (DFS: hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.30-1.77, p = 0.476; OS: HR, 0.36; 95% CI, 0.08-1.59, p = 0.178). Consistently, in the propensity score matched cohort, segmentectomy (n = 74) yielded similar DFS (p = 0.960) and OS (p = 0.320) with lobectomy (n = 74).

CONCLUSIONS

Segmentectomy could achieve comparable oncological outcomes with lobectomy for pure solid small-sized NSCLC.

Prognostic impact of the tumor volume doubling time in clinical T1 non-small cell lung cancer with solid radiological findings

BACKGROUND

The purpose of this study was to investigate better radiological prognostic factors in clinical T1 pure-solid non-small cell lung cancer (NSCLC).

METHODS

This study enrolled 284 patients with clinical T1 solid NSCLC who underwent anatomical lung resection. The Cox proportional hazard model was used to evaluate the prognostic impact of tumor volume doubling time (VDT) at disease-free survival (DFS) and cancer-specific survival (CSS).

RESULTS

The median VDT was 347 days. Age (hazard ratio (HR) = 1.04; 95% confidence interval (CI), 1.01-1.07) and standardized uptake value max (SUVmax) (>6.0) (HR = 2.61; 95% CI, 1.52-4.66) were identified as significantly independent worse prognostic factors for DFS in a multivariable analysis without VDT. Furthermore, a multivariable analysis without SUVmax identified age (HR = 1.06; 95% CI, 1.03-1.09), CEA (>5.0 ng/ml) (HR = 2.34; 95% CI, 1.30-4.02), tumor diameter on CT (>2.0 cm) (HR = 1.91; 95% CI, 1.18-3.13), and VDT (HR = 4.03; 95% CI, 2.41-6.93) as significantly independent worse prognostic factors for DFS.

CONCLUSIONS

The VDT value could be a useful prognostic factor in clinical T1 solid NSCLC.

Risk Factors for Occult Lymph Node Metastasis in Peripheral Non-Small Cell Lung Cancer with Invasive Component Size 3 cm or Less

BACKGROUND

In the seventh edition TNM staging system for lung cancer, a high maximum standardized uptake value (SUVmax) on positron emission tomography was regarded as a risk factor for occult lymph node metastasis in clinical T1N0 non-small cell lung cancer (NSCLC). However, in the eighth edition TNM classification, tumors are classified according to the size of the invasive component only, and those with invasive component size ≤3 cm are diagnosed as stage T1. The aim of this study was to reassess the risk factors for occult lymph node metastasis under the eighth edition TNM classification for lung cancer.

METHODS

From 2010 to 2017, 553 patients with clinical N0 peripheral NSCLC with invasive component size ≤3 cm underwent anatomical lobectomy with systematic lymph node dissection. We analyzed these cases retrospectively to identify risk factors for postoperative nodal upstaging.

RESULTS

Among 553 study patients, 54 (9.8%) had nodal upstaging after surgery. In multivariate analysis adopting the eighth edition TNM classification for lung cancer, serum carcinoembryonic antigen (CEA) level (hazard ratio [HR] = 1.113, p = 0.002), invasive component size (HR = 2.398, p = 0.004), visceral pleural invasion (HR = 2.901, p = 0.005), and lymphatic invasion (HR = 9.336, p < 0.001) were significant risk factors for nodal upstaging, but SUVmax was not.

CONCLUSION

SUVmax is not a predictor of nodal upstaging in clinical N0 peripheral NSCLC with invasive component size ≤3 cm under the eighth edition TNM classification for lung cancer. Significant risk factors of occult lymph node metastasis are serum CEA level, tumor invasive component size, visceral pleural invasion, and lymphatic invasion.

Volumetric assessment of solid pulmonary nodules on ultralow-dose CT: a phantom study

Background

To reduce the radiation exposure from chest computed tomography (CT), ultralow-dose CT (ULDCT) protocols performed at sub-millisievert levels were previously tested for the evaluation of pulmonary nodules (PNs). The purpose of our study was to investigate the effect of ULDCT and iterative image reconstruction on volumetric measurements of solid PNs.

Methods

CT datasets of an anthropomorphic chest phantom containing solid microspheres were obtained with a third-generation dual-source CT at standard dose, 1/8th, 1/20th and 1/70th of standard dose [CT volume dose index (CTDI_vol): 0.03-2.03 mGy]. Semi-automated volumetric measurements were performed on CT datasets reconstructed with filtered back projection (FBP) and advanced modelled iterative reconstruction (ADMIRE), at strength level 3 and 5. Absolute percentage error (APE) evaluated measurement accuracy related to the effective volume. Scan repetition differences were evaluated using Bland-Altman analysis. Two-way analysis of variance (ANOVA) assessed influence of different scan parameters on APE. Proportional differences (PDs) tested the effect of dose settings and reconstruction algorithms on volumetric measurements, as compared to the standard protocol (standard dose-FBP).

Results

Bland-Altman analysis revealed small mean interscan differences of APE with narrow limits of agreement (-0.1%±4.3% to -0.3%±3.8%). Dose settings (P<0.001), reconstruction algorithms (P<0.001), nodule diameters (P<0.001) and nodule density (P=0.011) had statistically significant influence on APE. Post-hoc Bonferroni tests showed slightly higher APE when scanning with 1/70th of standard dose [mean difference: 3.4%, 95% confidence interval (CI): 2.5-4.3%; P<0.001], and for image reconstruction with ADMIRE5 (mean difference: 1.8%, 95% CI: 1.0-2.5%; P<0.001). No significant differences for scanning with 1/20th of standard dose (P=0.42), and image reconstruction with ADMIRE3 (P=0.19) were found. Scanning with 1/70th of standard dose and image reconstruction with FBP showed the widest range of PDs (-16.8% to 23.4%) compared to standard dose-FBP.

Conclusions

Our phantom study showed no significant difference between nodule volume measurements on standard dose CT (CTDI_vol: 2 mGy) and ULDCT with 1/20th of standard dose (CTDI_vol: 0.10 mGy).

Prognosis of upstaged N1 and N2 disease after curative resection in patients with clinical N0 non-small cell lung cancer

Background

Nodal upstaging occasionally occurs after curative resection in clinical N0 non-small cell lung cancer (NSCLC). The purpose of this study was to evaluate the prognosis of clinical N0 NSCLC (T1-2, tumor size 5 cm or smaller) after upstaging to pathologic N1 or N2.

Methods

From 2005 to 2015, 676 consecutive patients were diagnosed with clinical T1-2N0 NSCLC and underwent curative resection. Among these, tumors were upstaged to N1 in 46 patients and to N2 in 24 patients. We analyzed the prognosis of upstaged tumors. For comparison of prognosis between nodal upstaging groups and others in the same stage, patients with preoperative pathologically proven N1 (n=31) and N2 (n=55) NSCLC were included in the study.

Results

A total of 70 patients (10.4%) had nodal upstaging after curative resection of clinical N0 NSCLC. Upstaging to N1 occurred in 46 patients and upstaging to N2 occurred in 24 patients. The 5-year disease-specific survival rate was not statistically different between the upstaged and non-upstaged N1/N2 groups in N1 disease (73.3% vs. 70.5%, P=0.247) or in N2 disease (58.9% vs. 50.7%, P=0.283). Multivariate analysis showed that nodal upstaging was not a significant prognostic factor in N1 or N2 NSCLC (hazard ratio =0.385, P=0.235; hazard ratio =0.677, P=0.458).

Conclusions

Postoperative nodal upstaging from clinical T1-2N0 NSCLC was not a significant prognostic factor in the same stage. Therefore, surgical treatment of clinical T1-2N0 lung cancer diagnosed by imaging without preoperative pathologic lymph node staging can be a treatment option.