The diagnosis and significance of visceral pleural invasion in lung carcinoma. Histologic predictors and the role of elastic stains

Diagnosis, treatment, and prognosis of stage IB non-small cell lung cancer with visceral pleural invasion

With the increasing implementation of early lung cancer screening and the increasing emphasis on physical examinations, the early-stage lung cancer detection rate continues to rise. Visceral pleural invasion (VPI), which denotes the tumor's breach of the elastic layer or reaching the surface of the visceral pleura, stands as a pivotal factor that impacts the prognosis of patients with non-small cell lung cancer (NSCLC) and directly influences the pathological staging of early-stage cases. According to the latest 9th edition of the TNM staging system for NSCLC, even when the tumor diameter is less than 3 cm, the final T stage remains T2a if VPI is present. There is considerable controversy within the guidelines regarding treatment options for stage IB NSCLC, especially among patients exhibiting VPI. Moreover, the precise determination of VPI is important in guiding treatment selection and prognostic evaluation in individuals with NSCLC. This article aims to provide a comprehensive review of the current status and advancements in studies pertaining to stage IB NSCLC accompanied by VPI.

Clinical Significance of Dual-Block Elastic Stain Evaluating Visceral Pleural Invasion in Peripheral Non-Small Cell Lung Cancer

Visceral pleural invasion (VPI) is a critical component in the staging of peripheral non-small cell lung carcinoma (NSCLC). We aim to investigate whether dual-block elastic stain increases visceral pleural invasion positivity compared with single-block elastic stain. We further analyze the potential predictors of visceral pleural invasion. 8419 peripheral NSCLC patients (including 6008 patients with tumor size≤3 cm in stage I) were divided into a cohort using one paraffin block (single-block group, n = 5184) and a cohort using dual paraffin blocks (dual-block group, n = 3235) for elastic stain. The VPI-positive rate demonstrated by the dual-block elastic stains group was significantly higher than that of the single-block elastic stain group (17.7% (573/3235) versus 9.1% (474/5184), respectively, P < .001). The presence of visceral pleural invasion in T1 (≤3 cm) patients detected by single- and dual-block elastic stain was 6.3% (235/3730) and 12.0% (273/2278), respectively (P < .001). 5.7% of T1 patients (stage IA) were additionally upstaged to T2a (stage IB) by dual-block elastic stain. However, the incidence of visceral pleural invasion in pT2a patients showed no significant difference between the single-block group and the dual-block group (16.8% vs. 17.1%, P = .916). Lymphovascular invasion, lymph node metastasis, dedifferentiated carcinomas, the presence of spread through airspaces (STAS) and a poorly differentiated adenocarcinomatous growth pattern could be significant predictors of visceral pleural invasion (P < .001). Our results indicate that using dual-block elastic stain identifies more visceral pleural invasion positive T1 NSCLC patients who are upstaged to T2a, and who could benefit from optimal management post-operatively. The application of dual-block elastic stain is an efficient and practical method to detect visceral pleural invasion status.

The prognosis of different types of pleural tags based on radiologic-pathologic comparison

Objectives

There are increasing numbers of studies of pleural tags (PTs). The purpose of this case series was to classify the PTs in patients with peripheral pulmonary adenocarcinoma based on radiologic-pathologic comparison and to study the prognosis.

Methods

The clinical, imaging, pathological and prognostic data of 161 patients with peripheral pulmonary adenocarcinoma in three hospitals were analyzed retrospectively. We classified PTs using computed tomography (CT) for pathologic comparison.

Results

According to the relationship between tumors and pleural on CT images, PTs were classified into four types: type 1, one or more linear pleural tag; type 2, one or more linear pleural tag with soft tissue component at the pleural end; type 3, one soft tissue cord-like pleural tag; type 4, directly abutting the visceral pleura, pulling or pushing the visceral pleura. In these PTs, the incidence of visceral pleural invasion (VPI) was high in type 2 (46.88%) and type 3 (56.41%) of PTs. Our prognostic analysis showed that micropapillary or solid histological subtype (HR = 5.766, 95% CI: 1.435–23.159, P = 0.014) and type 3 of PTs (HR = 11.058, 95% CI: 1.349–90.623, P = 0.025) were two independent risk factors for tumor progression.

Conclusions

PT is a risk factor for poor prognosis in patients with peripheral pulmonary adenocarcinoma, the presence of which on CT images can remind us to provide patients with a more reasonable treatment.

Modification of Pathologic T Classification for Non-small Cell Lung Cancer With Visceral Pleural Invasion: Data From 1,055 Cases of Cancers ≤ 3 cm

BACKGROUND

Visceral pleural invasion (VPI) with PL1 or PL2 increases the T classification from T1 to T2 in non-small cell lung cancers (NSCLCs) ≤ 3 cm. We proposed a modified T classification based on VPI to guide adjuvant therapy.

RESEARCH QUESTION

Is it reasonable to upstage PL1-positive cases from T1 to T2 for NSCLCs ≤ 3 cm?

STUDY DESIGN AND METHODS

In total, 1,055 patients with resected NSCLC were retrospectively included. Tumor sections were restained with hematoxylin and eosin stain and Victoria blue elastic stain for the elastic layer. Disease-free survival (DFS) and overall survival (OS) were calculated by the Kaplan-Meier method. Subgroup analysis and a Cox proportional hazards model were used to further determine the impact of VPI on survival.

RESULTS

The extent of VPI was diagnosed as PL0 in 824 patients, PL1 in 133 patients, and PL2 in 98 patients. The 5-year DFS rates of patients with PL0, PL1, and PL2 were 62.6%, 60.2%, and 28.8% (P < .01), whereas the corresponding 5-year OS rates were 78.6%, 74.4%, and 50.0% (P < .01), respectively. As predicted, the DFS and OS of patients with PL2 were much worse than those of patients with PL0 (P < .01) and PL1 (P < .01). However, both the DFS and OS of patients with PL0 and PL1 were comparable (DFS: P = .198; OS: P = .150). For node-negative cases, the DFS and OS of patients with PL0 and PL1 were also comparable (DFS: P = .468; OS: P = .388), but patients with PL2 had much worse DFS and OS than patients with PL0 (P < .01) and PL1 (P < .01). Multivariable analyses suggested that PL2, together with node positivity and poor cell differentiation, was an independent adverse prognostic factor.

INTERPRETATION

In NSCLCs ≤ 3 cm, tumors with PL1 should remain defined as T1, not T2. Overtreatment by adjuvant chemotherapy in node-negative NSCLCs ≤ 3 cm might be avoided in PL1 cases.

Extent of Visceral Pleural Invasion Affects Prognosis of Resected Non-small Cell Lung Cancer: A meta-analysis

Visceral pleural invasion (VPI) has been known to be an adverse prognostic factor in non-small cell lung cancer (NSCLC). However, the prognostic significance of extent of VPI (PL0, PL1 and PL2) remains controversial. We conduct a meta-analysis to summarize available evidence on this topic. PubMed, EMBASE, OVID and The Cochrane Library were searched for published studies from inception to May 9, 2016. A total of 16 studies were included in meta-analysis. Our results showed that patients with PL1 or PL2 had poorer overall survival compared with PL0 (HR = 1.555, 95% CI 1.399, 1.730; HR = 2.447, 95% CI 1.913, 3.130) and patients with PL2 had even poorer overall survival than PL1 (HR = 1.287, 95% CI 1.114, 1.487). Patients with PL1 or PL2 had lower 5-year survival rate than PL0 patients (OR = 0.515, 95% CI 0.415, 0.640; OR = 0.441, 95% CI 0.336, 0.579) and patients with PL2 had even lower 5-year survival rate than PL1 (OR = 0.706, 95% CI 0.545, 0.915). In conclusion, extent of VPI impacts the prognosis of resected NSCLC and VPI should be categorized as PL1 and PL2 in the terms of clinical practice and trials.

Peritoneal elastic lamina invasion: limitations in its use as a prognostic marker in stage II colorectal cancer

Peritoneal involvement in colorectal cancer (CRC) is an adverse prognostic feature, which may prompt consideration of adjuvant chemotherapy in stage II disease. Controversies and challenges surrounding its assessment have led to consideration of peritoneal elastic lamina invasion (ELI) as an alternative marker of advanced local spread. The objectives of this study were (1) to evaluate the prognostic significance of peritoneal ELI in stage II CRC and (2) to determine the feasibility of ELI assessment in routine practice with the use of an elastic stain. Two hundred seventeen patients with stage II CRC (186, pT3; 31, pT4) were assessed for ELI and other established adverse histologic features. Of the pT3 tumors, 31 (16.7%) were ELI positive, 121 (65%) were ELI negative, and 34 (18.3%) lacked an identifiable elastic lamina. There were no significant differences in disease-free survival between pT3 ELI-negative and ELI-positive tumors (P = .517). The disease-free survival of pT4 tumors was significantly lower than that of pT3 ELI-negative tumors (P = .024) and pT3 ELI-positive tumors (P = .026), respectively. The elastic lamina was detected less frequently in right-sided pT3 tumors compared with left-sided tumors (65/91 [71.4%] versus 87/95 [91.6%], P < .001). Right-sided tumors were also associated with a reduction in the staining intensity of the elastic lamina (P < .001). In conclusion, peritoneal ELI was not an adverse prognostic factor in this study. The frequent absence of an identifiable elastic lamina, particularly in right-sided tumors, may limit the use of ELI as a prognostic marker in CRC.

The format type has impact on the quality of pathology reports of oncological lung resection specimens

Most pathology reports are in a narrative form without a given structure and occasionally lack important information. Here we show that the format of pathology reports of oncological lung resection specimens correlates with the quality of the reports. All pathology reports of oncological lung resection specimens between 01/02 and 04/11 (N = 878) were classified into descriptive reports (DR, N = 249), structured reports (SR, N = 415) as well as template based synoptic reports (TBSR, N = 214) and compared regarding the content of organ specific essential data (ED). The amount of recorded ED was summarized in an essential data score (EDS). Median EDS of DR was 8, of SR 9, and of TBSR 10. Only 28.7% of all reports had an EDS of 10; divided into the report types 2.6% of DR, 16.4% of SR and 88.4% of TBSR obtained an EDS of 10 (paired comparison: P < 0.0001). Traditional descriptive reports showed the lowest quality sometimes lacking important information and clarity of data layout whereas the template based synoptic reports reached the highest quality level. The broader use of structured reports is recommended for oncological lung resection specimens as they lead to a reduction of failed data transfer and therefore to an increase of quality.

Are elastic stain and specialty sign out necessary to evaluate pleural invasion in lung cancers?

The seventh edition of American Joint Committee on Cancer (AJCC) staging system assigns lung cancers with visceral pleural invasion in the tumor size of 3 cm or less than 3 cm as T2 and without pleural invasion as T1. However, it may be difficult to distinguish with certainty between PL0 (no pleural invasion) and PL1 (extends through the elastic layer) on routine hematoxylin and eosin (H&E) stain. In this study, 25 cases of peripherally located lung adenocarcinoma were retrieved from the surgical pathology archives at the Asan Medical Center from May through June 2009. One representative H&E-stained slide was selected from each case and circulated to 31 pathology trainees and board-certified pathologists at Asan Medical Center who evaluated presence or absence of pleural invasion on H&E-stained slides. Elastic stain was used to determine the final status of pleural invasion for each case. The concordance rate of all pathologists with elastic stain results was, overall, 60.5%. The concordance rate of 2 lung specialists was 64%, better than the remaining faculty (54.7%). Fellows' and residents' evaluations were slightly more concordant than those of faculty responses (faculty overall, 56.4%; fellows, 62%; residents, 63.6%), but this difference was not statistically significant (P = .228). Our results confirm that pleural invasion status is difficult to discern with certainty on H&E-stained sections alone. Therefore, we recommend the routine use of elastic stain in evaluation of pleural invasion in all peripherally located lung cancers. Furthermore, our study indicates that subspecialty sign out may be preferable in evaluation of pleural invasion status.

A histochemical approach to the diagnosis of visceral pleural infiltration by non-small cell lung cancer

INTRODUCTION

Although invasion of the visceral pleura (VPI) by non-small cell lung cancer (NSCLC) is a TNM-relevant diagnostic criterion and is known to affect the patients' prognoses, until recently there were no standardized or internationally accepted guidelines. This resulted in a diagnostic ambiguity leading to different tumor staging systems and to hardly comparable patient collectives in research studies world wide. The major problem in this issue is to exactly define what constitutes for the diagnosis of VPI with respect to anatomical landmarks.

METHODS

In order to address this problem we investigated the pleural infiltration depth of 173 NSCLC specimens without lymph node metastases and proven tumor-related death using elastic stains and a scoring system referring to prominent pleural elastic layers, the lamina elastica externa and interna, as anatomical landmarks.

RESULTS

Performing comparative Kaplan-Meier survival analyses for each patient collective we could not find any significant difference in the patients' survival. This indicates that a differential evaluation of the tumor infiltration depth according to the elastic layers is not practicable.

CONCLUSIONS

Our findings support the consequent application of the recently proposed, pragmatic approach of the international staging committee for lung cancer (IASLC) to define an internationally accepted and standardized staging system for VPI.

Commonly encountered difficulties in pathologic staging of lung cancer

CONTEXT

Lung cancer is the leading cause of cancer mortality worldwide. Despite technological, therapeutic, and scientific advances, most patients present with incurable disease and a poor chance of long-term survival. For those with potentially curable disease, lung cancer staging greatly influences therapeutic decisions. Therefore, surgical pathologists determine many facets of lung cancer patient care.

OBJECTIVE

To present the current lung cancer staging system and examine the importance of mediastinal lymph node sampling, and also to discuss particularly confusing and/or challenging areas in lung cancer staging, including assessment of visceral pleura invasion, bronchial and carinal involvement, and the staging of synchronous carcinomas.

DATA SOURCES

Published current and prior staging manuals from the American Joint Committee on Cancer and the International Union Against Cancer as well as selected articles pertaining to lung cancer staging and diagnosis accessible through PubMed (National Library of Medicine) form the basis of this review.

CONCLUSIONS

Proper lung cancer staging requires more than a superficial appreciation of the staging system. Clinically relevant specimen gross examination and histologic review depend on a thorough understanding of the staging guidelines. Common sense is also required when one is confronted with a tumor specimen that defies easy assignment to the TNM staging system.

Impact of Elastic Staining on the Staging of Peripheral Lung Cancers

Accurate staging of lung cancer has a profound impact on patient management. For stage I nonsmall cell lung carcinomas (NSCLCs), the absence (stage IA) or presence (stage IB) of visceral pleural invasion represents a critical therapeutic branch point: patients with stage IB NSCLC benefit from adjuvant chemotherapy, whereas patients with stage IA NSCLC do not. Elastic staining has been advocated as a simple method for visualizing pleural invasion. The purpose of this study was to determine whether routine elastic staining of the resected peripheral NSCLCs alters tumor staging in a meaningful way. The study cases consisted of 100 consecutive peripheral NSCLCs resections that were pathologically staged as IA based on routine histologic assessment. Each case was stained with the Movats pentachrome elastic stain to aid identification of visceral pleural invasion. To assess current standards of surgical pathology practice, members of the American Association of Directors of Anatomic and Surgical Pathology were asked whether they never, sometimes, or always order elastic stains for peripheral NSCLCs that abut the pleura. Elastic staining resulted in a change of tumor stage from IA to IB in 19 (19%) cases. Of the 49 pathologists that responded to the survey, 25 (51%) never, 14 (29%) sometimes, and 10 (20%) always order an elastic stain for NSCLCs abutting the pleura. Elastic staining is currently not standard surgical pathology practice for the evaluation of peripheral NSCLCs, but it should be. Invasion of the pleura is an elusive finding that is best appreciated with an elastic stain. Our experience suggests that routine elastic tissue staining should be performed as a standard method of assessing pleural involvement for pleural-based nonsmall cell lung carcinomas.

Differential CT features of infectious pneumonia versus bronchioloalveolar carcinoma (BAC) mimicking pneumonia

The purpose of this study was to evaluate retrospectively the differential CT features of bronchioloalveolar carcinoma (BAC) mimicking pneumonia and infectious pneumonia at the lung periphery. CT images were reviewed in 47 patients with focal areas of parenchymal opacification at the lung periphery. We evaluated the presence of ground-glass attenuation, marginal conspicuity of the lesion, CT angiogram sign, air-bronchogram sign, a bubble-like low-attenuation area within the lesion, presence of pleural thickening and retraction associated with the lesion, presence of pleural effusion and extra-pleural fatty hypertrophy, presence of bronchial wall thickening proximal to the lesion, and air-trapping in the normal lung near the lesion. BAC (n=18) depicted the presence of a bubble-like low-attenuation area within the lesion, whereas infectious pneumonia (n=29) represented the pleural thickening associated with the lesion and bronchial wall thickening proximal to the lesion (P<0.05). The other CT findings showed no significant differences (P>0.05). The focal areas of the parenchymal opacification on the CT images may suggest infectious pneumonia rather than BAC when they show bronchial wall thickening proximal to the lesion and pleural thickening associated with the lesion, whereas BAC is characterized as the presence of a bubble-like low attenuation area within the tumor.

Classification of parietal pleural invasion at adhesion sites with surgical specimens of lung cancer and implications for prognosis

Parietal pleural invasion of non-small cell lung cancer (NSCLC) is a factor for poor prognosis, and a tumor of any size that invades the parietal pleura is classified as T3. However, with microscopic invasion beyond elastic fibers of the visceral pleura but no penetration to the parietal pleura at tight adhesion sites (we term this p1-3), classification as to the T factor is unclear. Among 1,179 consecutive patients with NSCLCs who underwent curative surgery between 1980 and 2002, 20 were in this category. Here, a comparison was made with subgroups of p stages IB, II, and IIIA with regard to histology, pleural invasion, and survival rates. To maximize the power of assessing prognostic potential, we set the significance level at 0.10, one-sided. The p1-3 condition sites of the 20 cases were the parietal pleura for 17 cases and the pericardium, diaphragm, and chest wall for one each of the remainder. The 5-year survival rate for these p1-3 patients was 71.6%. Significant differences were observed between p1-3 and IIIA groups. Although the 5-year survival rates did not significantly differ between p1-3 and T3N0 or unequivocal T3 subgroups, the prognosis of p1-3 patients was rather better than that of T3 and identical to T2. It was demonstrated that p1-3 status is not a factor warranting T3 classification for NSCLCs. Considering the prognosis, pathologic p1-3 tumors should be managed as a T2 disease for the present.

Visceral pleural invasion is an invasive and aggressive indicator of non-small cell lung cancer

OBJECTIVE

Although visceral pleural invasion by non-small cell lung cancer is considered a poor-prognostic factor, further information is lacking, especially in relation to other clinicopathologic prognostic factors. We assessed the relationship between visceral pleural invasion and other clinicopathologic characteristics and evaluated its significance as a prognostic factor.

METHODS

We reviewed 1074 patients with surgically resected T1/2 non-small cell lung cancer for their clinicopathologic characteristics and prognoses. The patients were divided into 2 groups according to visceral pleural invasion status (visceral pleural invasion group and non-visceral pleural invasion group). Both groups were compared with regard to age, sex, histology, tumor size, tumor differentiation, lymph node involvement, lymphatic invasion, vascular invasion, scar grade, nuclear atypia, mitotic index, serum carcinoembryonic antigen level, and survival. Univariate and multivariate analyses were conducted.

RESULTS

Visceral pleural invasion was identified in 288 (26.8%) of the resected specimens. Survival was 76.0% at 5 years and 53.2% at 10 years in the non-visceral pleural invasion group and was 49.8% at 5 years and 37.0% at 10 years in the visceral pleural invasion group. The difference between groups was highly significant ( P < .0001). Visceral pleural invasion was also significantly associated with a higher frequency of lymph node involvement. However, regardless of N status (N0 or N1/2), there was a significant difference in survival when the visceral pleura was invaded. Visceral pleural invasion was observed significantly more frequently in tumors with factors indicative of tumor aggressiveness/invasiveness: moderate/poor differentiation, lymphatic invasion, vascular invasion, high scar grade, high nuclear atypia grade, high mitotic index, and high serum carcinoembryonic antigen level. By multivariate analysis, visceral pleural invasion proved to be a significant independent predictor of poor prognosis in non-small-cell lung cancer patients with or without lymph node involvement.

CONCLUSIONS

Visceral pleural invasion is a significant poor-prognostic factor, regardless of N status. Our analyses indicated that visceral pleural invasion is an independent indicator of non-small cell lung cancer invasiveness and aggressiveness.

Visceral pleural invasion in lung cancer: recognizing histologic parameters that impact staging and prognosis

Visceral pleural involvement (VPI) is a critical component in the staging of non-small cell lung carcinoma (NSCLC). Tumors < or =3 cm that involve the visceral pleura are classified as T2 lesions, underscoring the prognostic significance of this histologic parameter. Accurate staging of small NSCLCs depends on appropriately assessing the presence or absence of VPI. Elastic stains can be instrumental in detecting disruptions of the visceral pleural elastic layer by tumor, a finding that has prognostic and staging implications similar to tumor that is present on the visceral pleural surface.

Prognostic value of visceral pleural invasion in resected non-small cell lung cancer diagnosed by using a jet stream of saline solution

OBJECTIVE

Visceral pleural invasion caused by non-small cell lung cancer is a factor in the poor prognosis of patients with that disease. We investigated the relationship between the diagnosis of visceral pleural invasion by using a jet stream of saline solution, which was previously reported as a new cytologic method to more accurately detect the presence of visceral pleural invasion, and prognosis.

METHODS

From January 1992 through December 1998, 143 consecutive patients with peripheral non-small cell lung cancer that appeared to reach the visceral pleura underwent a surgical resection at the Department of Thoracic Oncology, National Kyushu Cancer Center. The surface of the visceral pleura in patients undergoing lung cancer resection was irrigated with a jet stream of saline solution. The diagnosis of visceral pleural invasion was determined by means of either a pathologic examination or by means of a jet stream of saline solution. In addition, a cytologic examination of the pleural lavage fluid obtained immediately after a thoracotomy was evaluated.

RESULTS

Forty-nine (34%) resected tumors were identified as having visceral pleural invasion. The diagnosis of visceral pleural invasion in 31, 6, and 12 patients was determined by using a jet stream of saline solution alone, pathologic examination alone, or both, respectively. The visceral pleural invasion and positive findings of intrapleural lavage cytology were linked. Although there was no significant difference between the incidence of distant metastases in the patients with visceral pleural invasion and those without visceral pleural invasion, the incidence of local recurrence, especially regarding carcinomatous pleuritis (malignant pleural effusion, pleural dissemination, or both), in the patients with visceral pleural invasion was significantly higher than in those without visceral pleural invasion. The recurrence-free survival of patients with visceral pleural invasion was significantly shorter than that of patients without visceral pleural invasion (P =.004), even patients with stage I disease (P =.02). There was also a significant difference between the patients with or without visceral pleural invasion in the overall survival (P =.02). Visceral pleural invasion was independently associated with a poor recurrence-free survival on the basis of multivariate analyses (P =.03), as were sex (P =.03), age (P = 002), and the stage of the disease (P <.0001).

CONCLUSIONS

This study confirmed that the jet stream of saline solution method in addition to ordinary pathologic examination was useful for detecting visceral pleural invasion, which is considered to be one of the causes of local recurrence, especially in carcinomatous pleuritis.

Visceral pleural involvement in nonsmall cell lung cancer: prognostic significance

BACKGROUND

A tumor of any size that invades the visceral pleura is classified in the T2 category; however, the definition of the visceral pleural involvement has remained somewhat ambiguous. It is unclear whether the T2 category includes the p2 status alone or incorporates the extent of the p1 status.

METHODS

We retrospectively analyzed the survival of 474 patients with T1 and T2 nonsmall cell lung cancer to evaluate the influence of the degree of visceral pleural involvement (p0, p1, and p2) on the prognosis and to clarify the definition of the visceral pleural involvement.

RESULTS

The 5-year survival rates according to the degree of visceral pleural involvement were 68.0% in p0 (n = 345), 43.9% in p1 (n = 110), and 54.9% in p2 (n = 19; p0 versus p1, p = 0.0004; p0 versus p2, p = 0.013; and p1 versus p2, p = 0.61). The degree of visceral pleural involvement (p0 versus p1/p2) was a significant independent prognostic factor from tumor size and lymph node involvement, by multivariate analysis (relative risk = 1.47, p = 0.033). The prognosis of pN0 patients with p1 and tumor size 3 cm or less was significantly poorer than that of those with p0 and tumor size 3 cm or less (p = 0.0004), and the prognosis of patients with p1 and tumor size more than 3 cm was significantly poorer than that of those with p0 and tumor size more than 3 cm (p = 0.024).

CONCLUSIONS

The degree of visceral pleural involvement (p0 versus p1/p2) is an important component of the lung cancer staging system. Tumors with p1 and p2 status should be regarded as representing visceral pleural involvement and T2 disease.

The subserosal elastic lamina: an anatomic landmark for stratifying pT3 colorectal cancer

PURPOSE

Approximately 50 percent of all patients with resected colorectal carcinoma have tumors with pT3 status; however, no subclassifications of the penetration depth have been proposed. The purpose of this study is to evaluate the significance of histologic invasion beyond subserosal elastic lamina by colorectal carcinoma for postoperative recurrence and long-term survival after resection.

METHODS

pT3 colorectal carcinomas located above the peritoneal reflection were retrospectively classified into two depth grades (subserosal elastic lamina classification). Namely, "pT3-shallow" is defined as tumors those are confined above the subserosal elastic lamina, and "pT3-deep" is defined as tumors those penetrate beyond it. Based on subserosal elastic lamina classification, the 325 consecutive patients who underwent resections were divided into two groups, and then the clinicopathologic features, incidence of postoperative recurrence, and survival rates were compared between the two groups.

RESULTS

The overall postoperative recurrence rate in the pT3-deep group (35.2 percent) was higher than that in the pT3-shallow group (20.8 percent). In detail, liver and peritoneal recurrence rates in the pT3-deep group (19.7 percent, 7.7 percent, respectively) were higher than those in the pT3-shallow group (9.4 percent, 2.0 percent, respectively). There was a strong difference ( P < 0.0001) in overall survival rate between the pT3-deep group (5-year survival of 57.0 percent) and the pT3-shallow group (5-year survival of 78.6 percent). Multivariate analysis revealed that synchronous hematogenous metastasis ( P < 0.0001), lymph node metastasis ( P < 0.05), venous invasion ( P < 0.01), and subserosal elastic lamina classification ( P < 0.05) were the independent prognostic factors for postoperative survival.

CONCLUSIONS

The newly proposed subserosal elastic lamina classification is a useful subclassification to predict the prognosis of patients with resected pT3 colorectal carcinomas.

Diagnosis of visceral pleural invasion by lung cancer using intraoperative touch cytology

BACKGROUND

Invasion to the visceral pleura is an important component of lung cancer staging and an independent prognostic factor. However, the accuracy of pathologic examination depends on how the sections are made, and the pathologist may miss the most invaded part of the pleura. Therefore, we have designed "touch" cytology in an effort to more accurately diagnose the pleural invasion by lung cancer.

METHODS

Immediately after thoracotomy, the surface of the visceral pleura just above the tumor was gently touched by a glass slide without scrubbing in 100 patients who simultaneously underwent pleural lavage cytology or cytology of the subclinical pleural effusion.

RESULTS

Seventeen percent of the tumors were diagnosed as invading the visceral pleura by touch cytology. Lavage cytology was found to be positive in 7%. In reference to the pathologic examination of the tumor specimen, touch cytology was found to be positive in all of p3, 5 out of 6 of p2, 5 out of 30 of p1, and 5 out of 62 of p0 cases. Touch cytology correctly diagnosed all the positive cases detected by lavage or effusion cytology.

CONCLUSIONS

This study suggests that our method is useful in detecting the visceral pleural invasion and raises a possibility that pathologic p0 and p1 lung cancers include a subset of patients with tumor cells exposed on the pleural surface.