The prognostic impact of tumor size in resected stage I non-small cell lung cancer: Evidence for a two thresholds tumor diameters classification

Prognostic predictors of radical resection of stage I-IIIB non-small cell lung cancer: the role of preoperative CT texture features, conventional imaging features, and clinical features in a retrospectively analyzed

BACKGROUND

To investigate the value of preoperative computed tomography (CT) texture features, routine imaging features, and clinical features in the prognosis of non-small cell lung cancer (NSCLC) after radical resection.

METHODS

Demographic parameters and clinically features were analyzed in 107 patients with stage I-IIIB NSCLC, while 73 of these patients received CT scanning and radiomic characteristics for prognosis assessment. Texture analysis features include histogram, gray size area matrix and gray co-occurrence matrix features. The clinical risk features were identified using univariate and multivariate logistic analyses. By incorporating the radiomics score (Rad-score) and clinical risk features with multivariate cox regression, a combined nomogram was built. The nomogram performance was assessed by its calibration, clinical usefulness and Harrell's concordance index (C-index). The 5-year OS between the dichotomized subgroups was compared using Kaplan-Meier (KM) analysis and the log-rank test.

RESULTS

Consisting of 4 selected features, the radiomics signature showed a favorable discriminative performance for prognosis, with an AUC of 0.91 (95% CI: 0.84 ~ 0.97). The nomogram, consisting of the radiomics signature, N stage, and tumor size, showed good calibration. The nomogram also exhibited prognostic ability with a C-index of 0.91 (95% CI, 0.86-0.95) for OS. The decision curve analysis indicated that the nomogram was clinically useful. According to the KM survival curves, the low-risk group had higher 5-year survival rate compared to high-risk.

CONCLUSION

The as developed nomogram, combining with preoperative radiomics evidence, N stage, and tumor size, has potential to preoperatively predict the prognosis of NSCLC with a high accuracy and could assist to treatment for the NSCLC patients in the clinic.

Prediction and verification of survival in patients with non-small-cell lung cancer based on an integrated radiomics nomogram

AIM

To develop and validate a nomogram to predict 1-, 2-, and 5-year survival in patients with non-small-cell lung cancer (NSCLC) by combining optimised radiomics features, clinicopathological factors, and conventional image features extracted from three-dimensional (3D) computed tomography (CT) images.

MATERIALS AND METHODS

A total of 172 patients with NSCLC were selected to construct the model, and 74 and 72 patients were selected for internal validation and external testing, respectively. A total of 828 radiomics features were extracted from each patient's 3D CT images. Univariable Cox regression and least absolute shrinkage and selection operator (LASSO) regression were used to select features and generate a radiomics signature (radscore). The performance of the nomogram was evaluated by calibration curves, clinical practicability, and the c-index. Kaplan-Meier (KM) analysis was used to compare the overall survival (OS) between the two subgroups.

RESULT

The radiomics features of the NSCLC patients correlated significantly with survival time. The c-indexes of the nomogram in the training cohort, internal validation cohort, and external test cohort were 0.670, 0.658, and 0.660, respectively. The calibration curves showed that the predicted survival time was close to the actual survival time. Decision curve analysis shows that the nomogram could be useful in the clinic. According to KM analysis, the 1-, 2- and 5-year survival rates of the low-risk group were higher than those of the high-risk group.

CONCLUSION

The nomogram, combining the radscore, clinicopathological factors, and conventional CT parameters, can improve the accuracy of survival prediction in patients with NSCLC.

Oncologic Outcomes of Surgery Versus SBRT for Non-Small-Cell Lung Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

The optimal treatment of stage I non-small-cell lung carcinoma is subject to debate. The aim of this study was to compare overall survival and oncologic outcomes of lobar resection (LR), sublobar resection (SR), and stereotactic body radiotherapy (SBRT).

METHODS

A systematic review and meta-analysis of oncologic outcomes of propensity matched comparative and noncomparative cohort studies was performed. Outcomes of interest were overall survival and disease-free survival. The inverse variance method and the random-effects method for meta-analysis were utilized to assess the pooled estimates.

RESULTS

A total of 100 studies with patients treated for clinical stage I non-small-cell lung carcinoma were included. Long-term overall and disease-free survival after LR was superior over SBRT in all comparisons, and for most comparisons, SR was superior to SBRT. Noncomparative studies showed superior long-term overall and disease-free survival for both LR and SR over SBRT. Although the papers were heterogeneous and of low quality, results remained essentially the same throughout a large number of stratifications and sensitivity analyses.

CONCLUSION

Results of this systematic review and meta-analysis showed that LR has superior outcomes compared to SBRT for cI non-small-cell lung carcinoma. New trials are underway evaluating long-term results of SBRT in potentially operable patients.

Predictors of Distant Recurrence Following Stereotactic Body Radiation Therapy for Stage I Non-Small Cell Lung Cancer

OBJECTIVE

The objective of this study was to characterize patients at an increased risk of distant metastasis (DM) following stereotactic body radiation therapy (SBRT) for stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

We identified patients undergoing SBRT for stage I NSCLC between 2005 and 2016. Patients with a prior lung cancer diagnosis, receiving a biological effective dose <100 Gy, or receiving chemotherapy were excluded. Patients underwent pretreatment staging and were classified according to the American Joint Committee for Cancer (AJCC) 8th edition staging. The primary endpoint was DM. The Kaplan-Meier method and the Cox proportional hazards model were used for survival analysis and to identify predictors of DM.

RESULTS

A total of 174 patients were included, with a median age 75 years (range, 49 to 96 y) and a median follow-up of 24 months (range, 3 to 123 mo). The 2- and 4-year cumulative incidences of DM were 14.2% and 19.1%, respectively. Patients who developed DM had worse overall survival versus patients developing a locoregional recurrence (P=0.023). On multivariable analysis, having stage IB disease (hazard ratio: 2.95; 95% confidence interval: 1.06-8.23; P=0.039) or a lower/middle lobe tumor (hazard ratio: 2.67; 95% confidence interval: 1.07-6.69; P=0.036) was associated with increased risk of DM. The 2-year cumulative incidences of DM were 10.9% and 35.7% (P=0.002) for patients with stage IA versus IB tumors, respectively, and 11.3% and 19.7% (P=0.049) for patients with upper lobe versus lower/middle lobe tumors, respectively.

CONCLUSIONS

Patients with stage IB disease or lower/middle lobe tumors may have an increased risk of DM following SBRT. Randomized controlled trials are needed to further identify patients who may benefit from adjuvant systemic therapy after SBRT for stage I NSCLC.

External validation of the eighth edition of the TNM classification for lung cancer in 3,611 surgically treated patients at a single institution

BACKGROUND

A new revision of the tumor, node, metastasis (TNM) classification for lung cancer has been proposed by the International Association for the Study of Lung Cancer (IASLC), but external validation for it is required. This study aimed to evaluate stage groupings in the 8th edition of the TNM classification in an independent Chinese cohort.

METHODS

We retrospectively analyzed 3,611 patients who were diagnosed as stage I to IV non-small cell lung cancer (NSCLC) and who received surgical treatment at our institute in China between October 2009 and August 2017. Long-rank tests were used to compare survival between two adjacent stage groups.

RESULTS

Based on the 8th edition of the TNM classification, differences between every 2 adjacent stage groups were found to be significant except between Ia1 and Ia2 (P=0.062), and between IIIc and IVa (P=0.063). Significant differences were found between every 2 adjacent categories stratified by the T and N descriptors. Additionally, significant differences were found between M0 and M1a (P<0.001), while no significant difference was observed between M1a and M1b (P=0.092).

CONCLUSIONS

Our study provides an external validation of the stage groupings in the 8th edition of the TNM staging system in surgically treated Chinese patients with NSCLC.

Lymph node dissection and survival in patients with early stage nonsmall cell lung cancer: A 10-year cohort study

It is still debatable whether complete mediastinal lymph node dissection (MLND) is associated with better survival than mediastinal lymph node sampling (MLNS) in surgical treatment of nonsmall cell lung cancer (NSCLC). We aimed to assess the impact of lymph node dissection on long-term survival among stage I NSCLC patients.In this cohort study, 317 stage I NSCLC Chinese patients in Shanghai Chest Hospital were followed up for at least 10 years to evaluate the impact of different lymph node dissection modes on their survival. Among them, 161 patients were in the MLND group and 156 in the MLNS group. Overall survival and median survival times were calculated for the 2 groups. The association between lymph node dissection and the survival of NSCLC patients was assessed using Cox proportional-hazard models.Patients in the MLND group presented better survival (median survival time = 154.67 months) than those in the MLNS group (median survival time = 124.67 months). The MLNS had higher mortality than the MLND group, with the crude hazard ratio of the MLNS group relative to the MLND group as 1.32 (95% confidence interval [CI] 0.97, 1.78). After adjusting for age and sex, the association between lymph node dissection and mortality (hazard ratio 1.36, 95% CI 1.00, 1.84) was statistically significant (P = .047). Further adjusting for baseline clinical characteristics, the association (hazard ratio 1.40, 95% CI 1.02, 1.92) remained statistically significant (P = .036). The association between lymph node dissection mode and mortality was strong among patients with tumor size between 2.0 and 3.0 cm (hazard ratio 2.79, 95% CI 1.45, 5.37).We found that the MLND was associated with better survival for patients with early-stage NSCLC, compared with the MLNS. The effects of MLND on survival may depend on tumor size. Our findings have important implications in the treatment of early-stage NSCLC. Further prospective studies with a large sample size are needed to confirm our findings.

Relationship between tumor size and survival in non-small-cell lung cancer (NSCLC): an analysis of the surveillance, epidemiology, and end results (SEER) registry

INTRODUCTION

Tumor size is a known prognostic factor for early stage non-small-cell lung cancer (NSCLC), but its significance in node-positive and locally invasive NSCLC has not been extensively characterized. We queried the Surveillance, Epidemiology, and End Results database to evaluate the prognostic value of tumor size for early stage and node-positive and locally invasive NSCLC.

METHODS

Patients in Surveillance, Epidemiology, and End Results registry with NSCLC diagnosed between 1998 and 2003 were analyzed. Tumor size was analyzed as a continuous variable. Other demographic variables included age, gender, race, histology, primary tumor extension, node status, and primary treatment modality (surgery vs. radiation). The Kaplan-Meier method was used to estimate overall survival (OS). Cox proportional hazard model was used to evaluate whether tumor size was an independent prognostic factor.

RESULTS

In all, 52,287 eligible patients were subgrouped based on tumor extension and node status. Tumor size had a significant effect on OS in all subgroups defined by tumor extension or node status. In addition, tumor size also had statistically significant effect on OS in 15 of 16 subgroups defined by tumor extension and nodal status after adjustment for other clinical variables. Our model incorporating tumor size had significantly better predictive accuracy than our alternative model without tumor size.

CONCLUSIONS

Tumor size is an independent prognostic factor, for early stage and node-positive and locally invasive disease. Prediction tools, such as nomograms, incorporating more detailed information not captured in detail by the routine tumor, node, metastasis classification, may improve prediction accuracy of OS in NSCLC.

[Progress of Postoperative Adjuvant Chemotherapy in Stage I Non-small Cell Lung Cancer]

The morbidity and mortality of lung cancer rank the first place among all the malignant tumor. According to the histopathological characteristics, lung cancer is divided into non-small cell lung cancer (NSCLC) and small cell lung cancer. Only 20% patients diagnosed with NSCLC have the chance for surgery while their 5-yr overall survival is about 30%-60%. The therapeutic outcome of surgery alone is not satisfying. Adjuvant chemotherapy after surgical resection in stage II-IIIa lung cancer showed efficacy in many randomized clinical trials, but its role in stage I disease remains controversial. The choice of appropriate chemotherapy candidates, the selection of chemotherapy regimens and the research progress on biomarker are mainly discussed in this review.

[Research for mediastinal lymph node desection style of stage Ib upper lobe non-small cell lung cancer]

背景与目的

淋巴转移是肺癌最主要的转移途径，也是影响肺癌患者预后的主要因素之一。现有的研究显示上叶肺癌较之中、下叶肺癌更易发生区域性纵隔淋巴结转移。本研究回顾分析Ib期上叶非小细胞肺癌（non-small cell lung cancer, NSCLC）纵隔淋巴结清扫方式的选择及影响预后的相关因素。

方法

147例行肺上叶完全性切除术的NSCLC患者，其中左肺上叶71例，右肺上叶76例。术后病理均为Ib期（T2aN0M0）。术中共清扫淋巴结925枚，其中纵隔淋巴结491枚（上纵隔组266枚，下纵隔组225枚）。采用Kaplan-Meier乘积法和Log-rank检验对患者进行单因素生存分析，采用Cox回归模型进行多因素生存分析。

结果

① 单因素及多因素分析均显示：年龄、肿瘤直径及上纵隔淋巴结清扫站数是影响患者预后的重要因素；②对于Ib期右肺上叶NSCLC，#4组淋巴结与预后存在统计学意义（P=0.021），而对于Ib期左肺上叶NSCLC，#5组淋巴结与预后存在统计学意义（P=0.024）。

结论

对于Ib期上叶NSCLC而言，年龄、肿瘤直径及上纵隔淋巴结清扫站数是影响患者预后的重要因素；对于此类患者，采用肺叶特异性系统性淋巴结清扫或许是更为高效的手术方式。

Prognostic Factors for Survival of Stage IB Upper Lobe Non-small Cell Lung Cancer Patients: A Retrospective Study in Shanghai, China

OBJECTIVE

To identify clinical and pathologic factors that were associated with the survival of stage IB upper lobe non-small cell lung cancer (NSCLC) patients.

METHODS

A retrospective study of 147 subjects who had undergone curative resection for stage IB upper lobe NSCLC was performed. Patients who had received any adjuvant or neo-adjuvant chemotherapy were excluded. Survival function curves were estimated using the Kaplan-Meier procedure. Crude and adjusted hazard ratios (HRs) of potential prognostic factors were estimated using Cox proportional hazards models.

RESULTS

Five factors, including age, tumor size, histologic grade of differentiation, number of removed superior mediastinal lymph node stations and presence of visceral pleura invasion, were significantly and independently associated with mortality risk. Adjusted HRs were 2.6 [95% confidence interval (95% CI): 1.1-6.5] and 4.6 (95% CI: 1.9-11) for those aged 58-68 years and those >68 years, respectively, relative to those aged <58 years. HRs for those with poorly and moderately differentiated tumors were 6.4 (95% CI: 2.3-18) and 1.4 (95% CI: 0.7-2.8), respectively. HRs for those with tumor size 3.1-5 cm and >5 cm (vs≤3.0 cm) were 2.3 (95% CI: 1.1-4.9) and 4.3 (95% CI: 1.9-10), respectively. The presence of visceral pleura invasion also increased the risk of mortality (HR=4.0, 95% CI: 1.3-12).

CONCLUSION

Advanced age, larger tumor size, poorly differentiated histology, smaller number of removed superior mediastinal lymph node stations, and presence of visceral pleura invasion were associated with poor survival of surgically treated stage IB upper lobe NSCLC patients.

Correlation between tumor measurement on Computed Tomography and resected specimen size in lung adenocarcinomas

OBJECTIVE

To compare preoperative size of stage I and stage II lung adenocarcinoma as measured by Computed Tomography (CT) and as assessed on gross pathology specimens.

MATERIALS AND METHODS

47 patients diagnosed with stage I or II lung adenocarcinoma were evaluated. Institutional Review Board permission was obtained. Tumor contours were delineated using a semi-automated segmentation algorithm and adjusted based on a radiologist's input. Based on the tumor perimeter, maximal in-plane tumor diameter was calculated automatically. The largest single diameter from the pathology gross report was utilized. A paired t-test was used to examine the measurement difference between CT and pathology.

RESULTS

The mean largest diameter of the tumors at CT and pathology was 29.53 mm and 24.04 mm, respectively. There was a statistically significant difference between the mean CT measurement and mean pathology measurement of 5.49 mm (standard deviation 9.08 mm, p<0.001). The percent relative difference between the two measurements was 18.3% (standard deviation 28.2%).

CONCLUSION

There is a statistically significant difference between the tumor diameter as measured by CT and on pathology gross specimen. These differences could have implications in the treatment and prognosis of patients with early stage lung adenocarcinoma.

Prognostic impact of MMP-2 and MMP-9 expression in pathologic stage IA non-small cell lung cancer

BACKGROUND

The purpose of the present study was to assess the value of matrix metalloproteinase (MMP)-2 and MMP-9 expression and other potential prognostic factors in predicting the clinical outcome of patients after definitive surgery for pathologic stage IA non-small cell lung cancer (NSCLC).

METHODS

One hundred and forty-six consecutive and non-selected patients who underwent definitive surgery for stage IA NSCLC were included in this study. Formalin-fixed paraffin-embedded specimens were stained for MMP-2 and MMP-9, which were statistically evaluated for their prognostic value and other clinicopathological parameters.

RESULTS

Of the 146 patients studied, 102 (69.9%) cases were classified as having high expression for MMP-2. A total of 89 carcinomas (61.0%) had high expression for MMP-9. MMP-9 expression correlated with Eastern Cooperative Oncology Group (ECOG) performance status, pT stage, and differentiation (P = 0.005, <0.001, and <0.001, respectively). Vessel invasion, pT stage, and MMP-9 expression maintained their independent prognostic influence on overall survival (P = 0.037, <0.001, and <0.001, respectively).

CONCLUSIONS

From results of our relatively large database, MMP-9 may be considered as a viable biomarker that can be used in conjunction with other prognostic factors such as vessel invasion and pT stage to predict the prognosis of patients with completely resected pathologic stage IA NSCLC.

Early diagnosis of lung cancer using a SAFE-3000 autofluorescence bronchoscopy

The aim of the study was to evaluate the double modality working of a new autofluorescence videobronchoscope SAFE-3000 for the detection and localization of precancerous and malignant lesions. From April to May 2009, 168 patients underwent SAFE-3000 bronchoscopy using 'Twin Mode' and 'Multiple Image Xposition (MIX)' technologies. The study considers only 97 patients with morphological alterations (visual score 2 or 3) of mucosa; four bronchial biopsies (two for every modality) have been performed on every patient. Histological diagnosis of the 388 biopsies revealed normal mucosa in 11 patients, four benign lesions, 27 precancerous lesions and 55 malignant lesions. The sensitivity of the 'Twin Mode' and 'MIX' techniques in the characterization of premalignant and malignant lesions was 96% vs. 100%. The specificity was 60% in both of these technologies. SAFE-3000 autofluorescence bronchoscopy allows an early diagnosis of preneoplastic or neoplastic lesions according to the careful analysis of the bronchial mucosa, due to the complementarity of two modalities 'Twin Mode' and 'MIX'. Based on the relationship between the bronchoscopic goal and the histological results the MIX method contributes more of the new endoscopic technique findings.

Zone of transition: a potential source of error in tumor volume estimation

PURPOSE

To measure the width of the zone of transition (ZOT) between nonaerated solid tumor and surrounding nonneoplastic lung parenchyma and determine the extent to which ZOT influences computer-derived estimates of tumor volume based on computed tomographic (CT) images.

MATERIALS AND METHODS

This HIPAA-compliant study was approved by the institutional research board. The histologic slide containing the maximum tumor area was digitized for 20 consecutive patients with solid adenocarcinoma. The outer border of the tumor (A2) was marked; it included all lung parenchyma having any tumor cells. The inner border of the tumor (A1) was marked; it included only solid tumor where lung parenchyma was no longer preserved. Assuming two circles with areas of A2 and A1, the corresponding two radii, R2 and R1, were calculated. The average width of the ZOT was defined as R2 minus R1. The relationship between ZOT and tumor diameter on the CT images prior to surgery was assessed by using regression analysis. The relationship between ZOT and tumor volume was assessed by using a theoretical model of idealized spheres with varying diameters.

RESULTS

The mean width of the ZOT was 0.78 mm (median, 0.48 mm). The proportional effect of ZOT on tumor volume estimates decreased with increasing tumor diameter and increased with increasing width of ZOT. Correlation between ZOT and tumor diameter was not significant (P = .87).

CONCLUSION

The average width of ZOT is about a single pixel width on a full field of view CT scan; thus, the ZOT can have a large effect on volume estimates, particularly for small tumors.

Prognostic significance of intratumoral blood vessel invasion in pathologic stage IA non-small cell lung cancer

BACKGROUND

The 5-year survival rate of pathologic stage IA non-small cell lung cancer (NSCLC) is excellent; however, up to 10% of patients with pathologic stage IA NSCLC still relapse postoperatively and die. This study retrospectively analyzed the clinicopathologic features of patients with pathologic stage IA NSCLC to identify the prognostic factors and investigate the effect of a combination of intratumoral vessel invasion and tumor size.

METHODS

From December 1991 to December 2003, 217 consecutive patients with stage IA NSCLC were selected, and disease-free survival (DFS) was analyzed.

RESULTS

Intratumoral blood vessel invasion (BVI) was identified as an independent poor prognostic factor (p = 0.0006). The relative risk for patients with BVI was 4.599 times higher than that for patients without BVI (95% confidence interval, 1.913 to 11.056). According to the new T N M system, the difference in DFS between the patients with and without BVI was statistically significant, not only in tumors exceeding 2 cm (T1b with BVI vs T1b without BVI, p = 0.0020) but also in tumors smaller than 2 cm (T1a with BVI vs T1a without BVI, p < 0.0001). The survival curve of T1b patients without BVI was similar to that of T1a patients without BVI (p = 0.0892). Distant recurrence was frequently observed in both T1a and T1b patients with BVI.

CONCLUSIONS

BVI is an independent poor prognostic factor in patients with pathologic stage IA NSCLC. These T1a and T1b patients with BVI both might benefit from adjuvant chemotherapy.

Do evolving practices improve survival in operated lung cancer patients? A biobank may answer

INTRODUCTION

Biobanks may play a pivotal role in lung cancer patients' management, research, and health policy. The Nancy "Centre of Biologic Resources" analyzed the evolving profiles of operated lung cancer patients and their management over 20 years.

METHODS

A total of 1259 consecutive patients operated upon from 1988 till 2007 were included. Survival rates were statistically compared before and after 1997. The parameters associated with a significant improvement of survival were determined.

RESULTS

After 1997, lung cancer was diagnosed at an earlier stage. For Squamous Cell Lung Cancer (SQCLC), stages IA increased from 5.4 to 19.5% and for Adenocarcinoma (ADC), stage IA increased from 9.9 to 24.7%. More women with stage I ADC were operated upon after 1997 (p = 0.01). More patients with Large Cell Lung Cancer were diagnosed recently. Recent patients received more adjuvant or neo-adjuvant chemotherapy (p < 0.001) and less radiotherapy (stage I SQCLC: p = 0.019, stage I ADC: p < 0.001). A longer overall patients' survival was observed after 1997 (chi test for SQLC and ADC independently p < or = 0.002). Among SQCLC long survivors, those at stage I-II, below 50 years, were more numerous. A longer survival was associated with early stage in ADC patients. Stage was the single constant factor for overall outcome.

CONCLUSION

Overall and stage-adjusted survival of operated lung cancer patients has been improved in the last decade due mainly to earlier diagnosis. The generalized use of computed tomography scan, chemotherapy, and a collegial management improved patients' survival.

Tumor size matters differently in pulmonary adenocarcinoma and squamous cell carcinoma

Little about primary tumor size and nodal/distant metastases among different cell types in non-small cell lung cancer (NSCLC) was discussed. This study aimed to investigate distinct associations between tumor size and nodal/distant metastases in pulmonary adenocarcinoma and squamous cell carcinoma. The study also aimed to clarify the cutoff size relating to a higher likelihood of metastases. We retrospectively evaluated 932 NSCLC patients over a 3-year period and focused on cases with primary tumors less than 4.0 cm in size. Our data showed that 2.5 cm was the critical cutoff size regarding increased nodal/distant metastases in adenocarcinoma (p<0.001), but not in squamous cell carcinoma (p>0.05). In addition, the incidence of nodal/distant metastases reached a plateau of more than 80% in adenocarcinoma when the tumor size exceeded 2.5 cm. In contrast, there was no such correlation observed in squamous cell carcinoma. This study showed that tumor size mattered differently in pulmonary adenocarcinoma and squamous cell carcinoma.

Effect of formalin fixation on tumor size determination in stage I non-small cell lung cancer

BACKGROUND

Tumor size is an important prognostic factor in non-small cell lung cancer (NSCLC), but the American Joint Committee on Cancer staging system does not mandate a specific measurement method. Moreover, measuring fresh specimens and formalin-fixed specimens may yield disparate results. Our goal was to evaluate this disparity for stage I NSCLC.

METHODS

We enrolled 401 patients with stage I NSCLC who underwent surgical interventions and follow-up in our hospital between 1993 and 2002. Tumors invading visceral pleura, involving the main bronchus, or associated with atelectasis or obstructive pneumonitis were excluded. Tumor size was measured immediately after resection by surgeons and after formalin fixation by pathologists. Patients were assigned to one of three groups. Group 1 included 201 patients with tumors of 3 cm or less as indicated by both operation notes and pathology reports. Group 2 included 160 patients with tumors larger than 3 cm by both records. Group 3 included 40 patients with tumors larger than 3 cm according to operation notes but 3 cm or less according to pathology reports. Survival rates were compared.

RESULTS

Mean follow-up was 58 months. Five-year survival was 70.1% in group 1, 49.1% in group 2, and 51.1% in group 3. As expected, there was a significant survival difference between groups 1 and 2 (p < 0.001); however, there was also a difference between groups 1 and 3 (p = 0.006).

CONCLUSIONS

Formalin fixation may cause tumor shrinkage and migration from T2 to T1. For accurate tumor staging, size measurements should be performed immediately after resection instead of after formalin fixation. TNM staging should specify how to measure tumor size and the specimen status to be measured.

Prognostic significance of the non-size-based AJCC T2 descriptors: visceral pleura invasion, hilar atelectasis, or obstructive pneumonitis in stage IB non-small cell lung cancer is dependent on tumor size

BACKGROUND

The T2 descriptor for staging non-small cell lung cancer (NSCLC) contains several non-size-based criteria. It remains unknown whether the prognostic significance of these non-size-based criteria is dependent on tumor size.

METHODS

A total of 10,545 patients with stage IB NSCLC from the California Cancer Registry between 1989 to 2003 were categorized into the following three nonoverlapping criteria: (1) tumor size (T2S); (2) visceral pleura invasion, hilar atelectasis, or obstructive pneumonitis (T2P); and (3) main bronchus involvement > or = 2 cm from the carina (T2C). Univariate survival analyses were performed using the Kaplan-Meier method. Multivariate survival analyses were performed using Cox proportional hazards ratios.

RESULTS

A total of 51.1% of patients with stage IB NSCLC were staged by T2S, 43.2% by T2P, and 5.7% by T2C; 2,224 stage IB patients (total, 21.1%; 18.9% T2P + 2.2% T2C) had tumors < or = 3 cm in size. The 5-year survival rate and the median survival time of these stage IB patients with tumors < or = 3 cm in size were as follows: T2P, 51.2% and 64 months, respectively; T2C, 49.0% and 58 months, respectively. These values were similar to the 53.2% 5-year survival rate and 67-month median survival time for patients with stage IA NSCLC (p = 0.40). Cox proportional hazards model revealed T2P of > 3 cm was a poor prognostic factor for survival (vs T2S; hazard ratio [HR], 1.16; 95% confidence interval [CI], 1.08 to 1.24). Conversely, T2P < or = 3 cm was a favorable prognostic factor for survival (vs T2S; HR, 0.89; 95% CI, 0.82 to 0.96). T2C was not an independent prognostic factor for survival.

CONCLUSIONS

Prognostic significance of the non-size-based T2 descriptor T2P is dependent on tumor size.