Modified scar grade: a prognostic indicator in small peripheral lung adenocarcinoma

Fibroblastic reaction and vascular maturation in human colon cancers

PURPOSE

The objective of the present study was to provide evidence for the hypothesis of fibroblasts and the desmoplastic reaction, respectively, to impact the formation and maturation of the vascular network in human colon tumours via a retrospective in situ study. An in vivo xenograft model was evaluated to verify its potential for fibroblast-related functional studies.

MATERIALS AND METHODS

In situ: Fiftytwo G2/G3 colon tumours were histomorphologically categorised into low (<50%), medium (50-75%) and high (>75%) grade desmoplasia based on hematoxylin/eosin and Elastica van Gieson stained paraffin sections. Low and high grade desmoplastic tumours were identified and stained for endothelial and pericyte markers to morphometrically analyse microvessel count (MVC), vascular surface area (VSA) and vascular maturation status. In vivo: One out of three established subcutaneous xenograft model in NMRI (nu/nu) mice was adapted to monitor the impact of primary human fibroblasts on xenograft formation and morphology.

RESULTS

Vascular structures in human colon tumours are predominantly located in the fibroblastic stromal regions. Highly desmoplastic tumours, however, have significantly lower MVC and VSA values at the invasion front with signs for augmented vascular maturation as compared with low grade desmoplastic colon cancers. Our in vivo approach verified that only high proportions of co-injected normal fibroblasts accelerate xenograft formation of HCT-116 colon cancer cells.

CONCLUSIONS

The in situ data clearly support the hypothesis of fibroblasts to contribute to vascular maturation phenomena in colon cancers. The in vivo design of only 500 tumour cells co-injected with normal fibroblast is feasible, results in 100% engraftment and is the basis for further developments.

Carcinoma-associated fibroblasts are a rate-limiting determinant for tumour progression

Tumours are highly complex tissues composed of carcinoma cells and surrounding stroma, which is constructed by various different types of mesenchymal cells and an extracellular matrix (ECM). Carcinoma-associated fibroblasts (CAFs), which consist of both fibroblasts and myofibroblasts, are frequently observed in the stroma of human carcinomas, and their presence in large numbers is often associated with the development of high-grade malignancies and poor prognoses. Moreover, in human tumour xenograft models, CAFs extracted from the tumour are more capable of promoting tumour growth through their interactions with carcinoma cells when compared to those isolated from non-cancerous stroma. Taken together, these observations strongly suggest that CAFs actively contribute to tumour progression. In this review we highlight the emerging roles of these cells in promoting tumourigenesis, and we discuss the molecular mechanisms underlying their tumour-promoting capabilities and their cellular origin.

Molecular biology of cancer-associated fibroblasts: can these cells be targeted in anti-cancer therapy?

It is increasingly recognized that the non-neoplastic stromal compartment in most solid cancers plays an active role in tumor proliferation, invasion and metastasis. Cancer-associated fibroblasts (CAFs) are one of the most abundant cell types in the tumor stroma, and these cells are pro-tumorigenic. Evidence that CAFs are epigenetically and possibly also genetically distinct from normal fibroblasts is beginning to define these cells as potential targets of anti-cancer therapy. Here, we review the cell-of-origin and molecular biology of CAFs, arguing that such knowledge provides a rational basis for designing therapeutic strategies to coordinately and synergistically target both the stromal and malignant epithelial component of human cancers.

Genomics of lung cancer

This review focuses on recent research using genomics to examine lung carcinogenesis, histologic differentiation, and progression.

Subepithelial myofibroblast in lung adenocarcinoma: a histological indicator of excellent prognosis

We report here the presence of subepithelial myofibroblasts in pure bronchioloalveolar carcinoma and a subset of invasive lung adenocarcinoma. The subepithelial myofibroblasts we describe were observed in a peculiar location beneath the cancer cells in the alveolar septa. Immunohistochemically, they were positive for alpha-smooth muscle actin and calponin, but negative for desmin and h-caldesmon. To gain insight into their biological significance, we examined 116 surgically resected lung adenocarcinomas. The resected tumors included 13 bronchioloalveolar carcinomas, 20 mixed type adenocarcinomas with bronchioloalveolar carcinoma components, 57 papillary adenocarcinomas, 22 solid adenocarcinomas with mucin, and 4 acinar adenocarcinomas. All specimens were immunostained for alpha-smooth muscle actin to visualize the myofibroblasts. In all of the pure bronchioloalveolar carcinomas observed, the subepithelial myofibroblasts were completely preserved adjacent to the cancer cells. In mixed adenocarcinomas with bronchioloalveolar carcinoma components, subepithelial myofibroblasts were present in the bronchioloalveolar carcinoma components, but scanty in the invasive areas, where stromal myofibroblasts emerged between the cancer cell nests. Subepithelial myofibroblasts were retained, however, in the invasive areas of a subset of invasive adenocarcinomas. Survival analysis showed that the retention of subepithelial myofibroblasts in these invasive tumors was associated with low rates of lymphatic and vascular invasion, a low rate of lymph node involvement, and an excellent patient survival. These results suggest that subepithelial myofibroblasts increase in bronchioloalveolar carcinomas, but are gradually replaced by typical stromal myofibroblasts during progression into invasive cancer. A subset of invasive adenocarcinomas retains subepithelial myofibroblasts. Analysis of subepithelial myofibroblasts may be helpful in identifying a subset of lung adenocarcinoma with excellent prognosis.

Minimally invasive adenocarcinomas of the lung

Current World Health Organization (WHO) classification of lung adenocarcinomas includes noninvasive bronchioloalveolar carcinoma (BAC) and several patterns of invasive adenocarcinoma. The most common is a mixed subtype of adenocarcinoma. This group is very heterogenous and includes a wide spectrum of tumors ranging from adenocarcinomas with a dominant BAC growth pattern (lepidic growth) to frankly invasive adenocarcinoma with no BAC component. There is a tendency among clinicians to regard tumor as BAC if any significant amount of lepidic growth pattern within the tumor is identified. The change in WHO definition of BAC and introduction of mixed subtype of adenocarcinoma resulted in disconnect between surgical pathologists and clinicians regarding the use of terminology and criteria for diagnosis of BAC and mixed subtype of adenocarcinoma. It is clear that pure BAC is an extremely rare tumor, whereas mixed subtypes of adenocarcinomas may have various clinical presentations and outcomes. The mounting evidence suggests that a subset of mixed subtype of adenocarcinomas with areas of BAC and focal invasion probably represent more indolent tumors. On the basis of the published data, there is a proposal to define a subcategory of "minimally invasive adenocarcinoma" of the lung. Many morphologic factors seem to play a role in predicting the behavior of these tumors. Depending on the results of ongoing clinical trials, surgical management of these tumors may change in a near future.

Invasive size is an independent predictor of survival in pulmonary adenocarcinoma

Current classification of pulmonary adenocarcinoma includes noninvasive bronchioloalveolar carcinoma, mixed subtype adenocarcinoma, and several patterns of invasive carcinoma. The extent of invasion in mixed subtype adenocarcinoma is variable, and prior studies suggest that estimates of extent of desmoplasia or invasion and gross tumor size are predictors of survival. Pathologic review of 178 consecutive primary lung adenocarcinoma resections from 1997 to 2000 was performed blinded to outcome. Lymph node metastases were not present in adenocarcinomas with less then 0.6 cm of invasion. In multivariate analysis and in strata adjusted for stage, measurement of linear extent of invasion was significantly associated with survival whereas gross size measurement alone was not. Significant differences in median survival were observed when patients were divided into noninvasive, microinvasive (<0.6 cm invasion), and invasive subcategories. In conclusion, among lung adenocarcinomas, histologic assessment of invasive growth may provide valuable prognostic information, and tumors with invasion under 0.6 cm have a more indolent clinical course after resection.

Imatinib mesylate inhibits proliferation and exerts an antifibrotic effect in human breast stroma fibroblasts

Tumor stroma plays an important role in cancer development. In a variety of tumors, such as breast carcinomas, a desmoplastic response, characterized by stromal fibroblast and collagen accumulation, is observed having synergistic effects on tumor progression. However, the effect of known anticancer drugs on stromal cells has not been thoroughly investigated. Imatinib mesylate is a selective inhibitor of several protein tyrosine kinases, including the receptor of platelet-derived growth factor, an important mediator of desmoplasia. Recently, we have shown that imatinib inhibits the growth and invasiveness of human epithelial breast cancer cells. Here, we studied the effect of imatinib on the proliferation and collagen accumulation in breast stromal fibroblasts. We have shown that it blocks the activation of the extracellular signal-regulated kinase and Akt signaling pathways and up-regulates cyclin-dependent kinase inhibitor p21(WAF1), leading to the inhibition of fibroblast proliferation, by arresting them at the G(0)/G(1) phase of the cell cycle. Imatinib inhibits more potently the platelet-derived growth factor-mediated stimulation of breast fibroblast proliferation. By using specific inhibitors, we have found that this is due to the inhibition of the Akt pathway. In addition, imatinib inhibits fibroblast-mediated collagen accumulation. Conventional and quantitative PCR analysis, as well as gelatin zymography, indicates that this is due to the down-regulation of mRNA synthesis of collagen I and collagen III-the main collagen types in breast stroma-and not to the up-regulation or activation of collagenases matrix metalloproteinase 2 and matrix metalloproteinase 9. These data indicate that imatinib has an antifibrotic effect on human breast stromal fibroblasts that may inhibit desmoplastic reaction and thus tumor progression.

Histological evaluation of the effect of smoking on peripheral small adenocarcinomas of the lung

INTRODUCTION

As there is little information on the histologic characteristics of adenocarcinoma in smokers, we histologically examined the effect of smoking on the carcinogenesis and progression of peripheral small lung adenocarcinomas.

METHODS

Two hundred thirty-six consecutive patients with peripheral adenocarcinoma of the lung 30 mm or less in diameter were studied. Prognosis, histology, and location of the adenocarcinoma were compared among patients with a Brinkman index (B.I.) of 0, 1 to 500, and more than 500.

RESULTS

The ratio of smokers to nonsmokers was 1.4:1. The rate of carcinogenesis in the upper region of the lung (S1-3) was 1.4 times as high that in the lower region (S4-10) in smokers, but almost equal in the two regions in nonsmokers. Outcome tended to be worse in patients with a B.I. of more than 500 than in those with a B.I. of less than or equal to 500 for adenocarcinomas 30 mm or less in diameter (p = 0.0855), and was significantly worse for adenocarcinomas 20 mm or less in diameter (p = 0.0359). Patients with a high B.I. tended to have invasive adenocarcinoma (IAC) without a bronchioloalveolar carcinoma (BAC) component (IAC - BAC) or IAC with a BAC component (IAC + BAC) rather than noninvasive adenocarcinoma. For adenocarcinomas as a whole, B.I. was correlated with several pathologic prognostic factors, including pathologic stage, lymphatic permeation, vascular invasion, presence of a solid component, necrosis, and modified scar grade, particularly in the upper region. Specifically, in IAC + BAC, B.I. was correlated with modified scar grade and the presence of a solid component. In IAC - BAC, B.I. was correlated with the presence of a solid component and necrosis.

CONCLUSIONS

Small adenocarcinoma in smokers seems to occur frequently in the upper region of the lung, shows invasive features more frequently, and shows greater progression and dedifferentiation than that in nonsmokers. Tobacco-smoking may have an effect on the carcinogenesis and multistep progression of peripheral lung adenocarcinoma 30 mm or less in diameter.

A fibrotic focus is a prognostic factor and a surrogate marker for hypoxia and (lymph)angiogenesis in breast cancer: review of the literature and proposal on the criteria of evaluation

A fibrotic focus is a scar-like area in the centre of a carcinoma and can be regarded as a focus of exaggerated reactive tumour stroma formation. Although modern surgical pathology uses different histopathological and molecular markers to assess the aggressiveness and predict the behaviour of malignant tumours, markers reflecting stromal cell behaviour and interactions between epithelial cells and stromal cells are scarce. In this review we summarize all studies investigating the value of a fibrotic focus as a prognostic factor and as a surrogate marker for hypoxia and (lymph)angiogenesis in patients with breast cancer. These data show that a fibrotic focus can be used as a practical, easily assessable and reproducible integrative histological prognostic parameter in breast cancer. We propose a consensus methodology to assess the fibrotic focus in breast cancer.

Micropapillary pattern and grade of stromal invasion in pT1 adenocarcinoma of the lung: usefulness as prognostic factors

Recently, the stromal invasion grading system was proposed for small adenocarcinomas of < or =2.0 cm. The system is based on the presence or absence of a fibrotic focus, and the extent of invasion into the fibrotic focus. Although stromal invasion grading system closely correlated with the prognosis, stromal invasion grade 3, representing stromal invasion into the center of a fibrotic focus, was the largest group of tumors and showed variable prognosis. In this study, we investigated whether stromal invasion grading system could be applied to and validated in pT1 adenocarcinomas as the TNM classification is the most universally used system. Furthermore, we investigated whether stromal invasion grade 3 cases could be subclassified according to the presence and absence of micropapillary pattern. The study included 120 cases of pT1 lung adenocarcinomas, of which 81 (68%) cases were stromal invasion grade 3. Micropapillary pattern was positive in 80% of grade 3 cases. For stromal invasion grade 3 cases, the 5-year survival rate of patients with micropapillary pattern-positive carcinomas was 63%, which was significantly worse than 94% of those with micropapillary pattern-negative carcinomas (P=0.0196). The latter was very close to that for patients with stromal invasion grade 0-2 (95%). Moreover, small cluster invasion was observed at sites of stromal invasion significantly more often in micropapillary pattern-positive cases than negative cases. Thus, the stromal invasion grading system is reproducible and correlates with prognosis even in pT1 lung adenocarcinomas. Moreover, among patients with stromal invasion grade 3 carcinomas, favorable prognosis is noted in micropapillary pattern-negative cases. The micropapillary pattern subclassification provides an advantage to the stromal invasion grading system and reconfirms the importance of micropapillary pattern as a prognostic marker. Our study is the first to point to the possible association of micropapillary pattern-positive carcinomas and small cluster invasion.

Small peripheral pulmonary adenocarcinoma: morphologic and molecular update

The dichotomous histopathologic separation of lung carcinoma into "small cell" and "nonsmall cell" categories is validated by marked clinical and biologic differences between these groups of tumors. However, nonsmall cell carcinoma represents a heterogenous group of tumors, and the subclassification of nonsmall cell lung carcinoma at the molecular, morphologic, and epidemiologic levels has led to the promise of precise treatment and better prognostication. Histomorphologic aspects of small peripheral adenocarcinomas that represent good prognosis include pure bronchioloalveolar carcinoma, minimal invasion within a mixed invasive and lepidic growth pattern tumor, and minimal scar within a lepidic growth pattern tumor. Activating mutations and increased gene copy number of the epidermal growth factor receptor protein and locus, respectively, have been shown to help predict responsiveness to small molecule receptor tyrosine kinase inhibitors in lung adenocarcinoma. These important concepts of morphology and molecular pathology are reviewed, and recommendations for application of these concepts to the practice of surgical pathology are provided.

SPARC enhances tumor stroma formation and prevents fibroblast activation

Tumor growth is influenced by interactions between malignant cells and the tumor stroma. Although the normal host microenvironment is nonpermissive for neoplastic progression, tumor-reactive stroma, characterized by the presence of activated fibroblasts, promotes neoplastic growth and metastasis. Secreted protein, acidic and rich in cysteine (SPARC) is a matricellular glycoprotein that is capable of inhibiting the growth of several different types of cancer. Recently, we reported that SPARC also impairs the growth of xenografts comprised of 293 cells. In this study, we show that in addition to enhancing stroma formation, SPARC prevents fibroblast activation in 293 xenografts, suggesting that the anti-cancer effects of SPARC may be due, at least in part, to the formation of tumor stroma that is not supportive of tumor growth. In vitro, 3T3 fibroblasts cocultured with SPARC-transfected 293 cells remain negative for alpha-smooth muscle actin, whereas wild-type 293 cells induce fibroblast activation. Moreover, activation of 3T3 cells and primary fibroblasts by transforming growth factor beta is blocked by SPARC treatment. We also demonstrate that SPARC significantly increases basic fibroblast growth factor-induced fibroblast migration in vitro, indicating that it may recruit host fibroblasts to the tumor stroma. Taken together, our results suggest that in addition to blocking angiogenesis, SPARC may inhibit tumor growth by promoting the assembly of stroma that is non-permissive for tumor progression.

Prognostic significance of a histologic subtype in small adenocarcinoma of the lung: the impact of nonbronchioloalveolar carcinoma components

BACKGROUND

We tried to clarify whether the histologic subtypes and the size of the solid component of an adenocarcinoma are more important predictive factors for invasiveness or prognosis than is total tumor size, even in lung adenocarcinomas that were 2 cm or smaller.

METHODS

Between 1996 and December 2005, after standard surgical treatment, 82 patients were diagnosed as having adenocarcinoma with a maximum diameter of 2 cm or less. The group comprised 37 females and 45 males, with ages ranging from 41 to 80 years (median, 64). The clinicopathologic records of the patients were examined with regard to age, sex, nodal status, tumor size (largest diameter of the total tumor as well as the largest diameter without the bronchioloalveolar carcinoma [BAC] component [solid component]), serum carcinoembryonic antigen level, and histologic type. These variables were analyzed as risk factors for vascular or lymphatic invasion, lymph node metastasis, and prognosis. Histologic subtype was classified into two groups: mixed BAC (mixed adenocarcinoma with BAC) and minimal or non-BAC (tumors with little or no BAC component).

RESULTS

Histologic subtype was a significant predictive factor both for invasiveness (vascular or lymph vessels) and lymph node metastasis, in both univariate and multivariate analysis. Tumor diameter was not a significant factor in either univariate or multivariate analysis (p = 0.28, 0.15, respectively). However, diameter excluding the BAC component was a significant factor for invasiveness in mixed BAC type (p = 0.035), whereas total diameter was not significant (p = 0.28). Finally, histologic subtype and lymph node metastasis were significant prognostic factors for survival in both univariate (p = 0.03, 0.05, respectively) and multivariate (p = 0.04, 0.05, respectively) analyses. The 5-year survival rate was 94.4% (94.1% for pN0) for the mixed BAC type and 71.4% (78.7% for pN0) for the minimal or non-BAC type (p = 0.009; p = 0.04 for pN0 nodes).

CONCLUSIONS

Small adenocarcinomas can be classified into two categories. The first category is a minimal or non-BAC adenocarcinoma that shows aggressive biological behavior. The second category is a mixed BAC, which demonstrates less invasive or aggressive biological behavior than the minimal or non-BAC type, with the degree of invasiveness being associated with the size of the non-BAC component.

Small adenocarcinoma of the lung: prognostic significance of central fibrosis chiefly because of its association with angiogenesis and lymphangiogenesis

To clarify the reason why central fibrosis (CF) is an important histological prognostic factor in small adenocarcinoma (SA) of the lung, tumor tissues from 50 patients with SA < or = 2 cm in diameter were investigated using immunohistochemical and in situ hybridization analysis for factors relating to extracellular matrix and vessels. CF was observed in 33/50 cases (66%). In adenocarcinoma areas, positive activity was observed with both primary antibodies and probes for matrix metalloproteinase-2 (MMP-2) in 11/50 patients (22%), membrane-type 1 matrix metalloproteinase (MT1-MMP) in 39/50 patients (78%) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in 49/50 patients (98%). In CF areas, the positive activity of fibroblastic cells was seen for only TIMP-2 in 32/33 patients (97%). In CF areas, both CD34-positive (blood and lymphatic) vessels and D2-40-positive lymphatic vessels were semiquantitatively increased in 16/33 patients (48.5%) by immunohistochemistry. Tumors with increased vessel density were associated with statistically lower disease-free survival curves compared with tumors without increased vessels. Lymphatic vessels in some CF showed intravasation by carcinoma cells. In conclusion, CF could be an important histological prognostic factor in SA chiefly because of its association with angiogenesis and lymphangiogenesis.

Stromal fibroblasts present in invasive human breast carcinomas promote tumor growth and angiogenesis through elevated SDF-1/CXCL12 secretion

Fibroblasts often constitute the majority of the stromal cells within a breast carcinoma, yet the functional contributions of these cells to tumorigenesis are poorly understood. Using a coimplantation tumor xenograft model, we demonstrate that carcinoma-associated fibroblasts (CAFs) extracted from human breast carcinomas promote the growth of admixed breast carcinoma cells significantly more than do normal mammary fibroblasts derived from the same patients. The CAFs, which exhibit the traits of myofibroblasts, play a central role in promoting the growth of tumor cells through their ability to secrete stromal cell-derived factor 1 (SDF-1); CAFs promote angiogenesis by recruiting endothelial progenitor cells (EPCs) into carcinomas, an effect mediated in part by SDF-1. CAF-secreted SDF-1 also stimulates tumor growth directly, acting through the cognate receptor, CXCR4, which is expressed by carcinoma cells. Our findings indicate that fibroblasts within invasive breast carcinomas contribute to tumor promotion in large part through the secretion of SDF-1.

Expression and localization of mRNAs for matrix metalloproteinases and their inhibitors in mixed bronchioloalveolar carcinomas with invasive components

Matrix metalloproteinases (MMPs) are believed to play an essential role in cancer invasion, although detailed differences between noninvasive and invasive lung carcinomas are still unclear. To elucidate the expression and activity patterns of MMPs in noninvasive and invasive carcinoma of the lung, we performed in situ hybridization and real-time reverse transcription-polymerase chain reaction to detect messenger RNAs (mRNAs) of MMPs and their tissue inhibitors (TIMPs). The basement membrane was evaluated by immunohistochemistry for type IV collagen. Gelatinase activity was examined by zymography and in situ zymography. A total of 14 surgically resected primary pulmonary adenocarcinomas were used for this study. All the tumors were adenocarcinoma mixed bronchioloalveolar carcinomas according to the 1999 WHO classification. MMP and TIMP2 mRNAs were detected by in situ hybridization in all samples, in both noninvasive and invasive carcinoma components. Signals for MMP mRNAs were significantly higher in both noninvasive and invasive carcinomas than in tumor-free lung tissue. However, the differences were small between noninvasive and invasive carcinomas, not only in the amount of mRNA but also in the activity of the MMPs. In most carcinomas, stromal fibroblast-type cells tended to express levels of MMP and TIMP2 mRNAs that were higher than or at least similar to those expressed in epithelial cells. Our data on mixed adenocarcinoma suggest that noninvasive carcinoma areas already express a molecular mechanism involving MMPs similar to that expressed by invasive carcinoma areas. Stromal fibroblast-type cells seem to be the most important source of MMPs, from the earliest event of tumor invasion by pulmonary adenocarcinomas.

Prognostication of small-sized primary pulmonary adenocarcinomas by histopathological and karyometric analysis

To reveal useful prognostic factors in cases of small-sized pulmonary adenocarcinoma, we conducted a histological and karyometric analysis of 116 small-sized pulmonary adenocarcinomas measuring less than 2 cm in maximum diameter and four specimens of atypical adenomatous hyperplasia (AAH). The small-sized pulmonary adenocarcinomas were classified by using criteria described previously [Noguchi M, Morikawa A, Kawasaki M, et al. Small adenocarcinoma of the lung. Histologic characteristics and prognosis. Lung Cancer 1995:75;2844-52]. There were 99 tumors of replacement-type adenocarcinoma, comprising 11 type A, localized bronchioloalveolar adenocarcinoma (LBAC); 6 type B, LBAC with alveolar collapse; and 82 type C, LBAC with foci of fibroblastic proliferation. The 17 remaining tumors were non-replacement-type adenocarcinomas. Among the potential prognostic factors examined, histological subtype was the most closely correlated with 5-year relapse-free survival rate. Furthermore, in patients with type C adenocarcinomas, a small fibroblastic proliferation (F) to fibrosis area (f) ratio (F-f ratio) (<10%) of the tumor and a small maximum nuclear diameter (Max ND; <13.50 microm) of tumor cells were closely associated with an excellent prognosis. Histological subtypes of type A and B adenocarcinomas, a small F-f ratio, and a small Max ND of type C adenocarcinomas were closely correlated with an excellent prognosis in small-sized adenocarcinoma.

Current status of small peripheral adenocarcinomas of the lung and their importance to pathologists

There has been a large amount of work done recently on small peripheral stage I adenocarcinomas that come to resection. Radiological (including proportion of ground glass opacity) and pathological features of these lesions (predominant bronchioloalveolar component, central scar with or without invasion <0.5 cm) have been shown to be prognostically favorable with cure rate approaching 100% in some series. Most of these studies emanate from Japan. The relevance of these studies to other parts of the world, particularly North America, is discussed in light of the fact that some recent chemotherapeutic studies with gefitinib have shown increased response in individuals of Asian origin, suggesting that some genetic differences may be significant. The relevance of these findings to pathologists and the pathological study of small peripheral adenocarcinomas from elsewhere in the world are discussed.

Surgically Curable Peripheral Lung Carcinoma

STUDY OBJECTIVES

To define characteristics of surgically curable, early cancers of the lung, we retrospectively studied relationships between thin-section CT (TS-CT) scans, pathologic features, and outcome data in 287 patients with resected small-diameter (< 20 mm) peripheral lung carcinoma. Cases included 260 adenocarcinomas, 16 squamous cell carcinomas, 6 small cell carcinomas, 3 large cell carcinomas, and 2 others.

MEASUREMENTS AND RESULTS

All tumors were classified by tumor shadow disappearance rate (TDR) on TS-CT as having either an "air-containing" or "solid-density" pattern. Adenocarcinomas are typically classified into these patterns. Air-containing patterns (n = 136) showed 1% pleural involvement and 2% vascular invasion, with no lymphatic permeation by pathology. Solid-density patterns (n = 124) showed 34% pleural involvement, 42% vascular invasion, and 29% lymphatic permeation. No cases of relapse or death were observed in cases with the air-containing pattern, in contrast to the high relapse and death rate in solid-density cases (p < 0.0001). All non-adenocarcinoma cases (n = 25) had a solid-density pattern, with 4% pleural involvement, 52% vascular invasion, and 44% lymphatic permeation. The overall 5-year survival rate for non-adenocarcinoma was 60%, similar to that for solid-density adenocarcinoma.

CONCLUSIONS

When peripheral lung cancers < 20 mm in diameter show air-containing patterns on TS-CT images, surgical outcomes may be favorable with curable disease.

Desmoplasia measured by computer assisted image analysis: an independent prognostic marker in colorectal carcinoma

AIMS

The assessment of desmoplasia by traditional semiquantitative methods does not provide reliable prognostic data. The aim of this study was to quantify desmoplasia by computerised image analysis in primary colorectal carcinomas and to investigate its ability to predict overall survival.

METHODS

In total, 112 colorectal adenocarcinomas, with a median follow up of 66 months, were studied. The representative tumour sections were stained by the van Gieson method, which stains collagen rich stroma red. For quantitative histochemical measurement, digital images were analysed by a computerised image analysis program to calculate the percentage of red stained tissue area. The percentage of desmoplasia (PD) was related to conventional clinicopathological prognostic factors and overall survival.

RESULTS

The mean (SD) PD was 4.85 (3.37). PD was found to be significantly associated with lymph vessel and venous invasion. By Kaplan-Meier analysis, PD was associated with survival-patients with PD > 4 had a shorter survival than those with PD

CONCLUSION

Desmoplasia measured by image analysis seems to be a significant prognostic indicator in patients with colorectal carcinoma and the improved method described in this study would be useful for routine prognostication.

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Key Words

• desmoplasia
• colorectal carcinoma
• prognosis
• quantitative histochemistry
• image analysis

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MESH Headings

• Adenocarcinoma/pathology
• Adenocarcinoma/secondary
• Adult
• Aged
• Aged, 80 and over
• Blood Vessels/pathology
• Colorectal Neoplasms/pathology
• Fibrosis
• Follow-Up Studies
• Humans
• Image Processing, Computer-Assisted/methods
• Lymphatic Vessels/pathology
• Middle Aged
• Neoplasm Invasiveness
• Neoplasm Staging
• Prognosis
• Reproducibility of Results
• Survival Analysis

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Affiliation(s)

B Sis Department of Pathology, Dokuz Eylül University School of Medicine, Inciralti, Izmir 35340, Turkey
S Sarioglu
S Sokmen
M Sakar
A Kupelioglu
M Fuzun

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Predictive factors for survival in surgically resected clinical IA peripheral adenocarcinoma of the lung

BACKGROUND

Patients with clinical IA (C-IA) lung cancer have a 5-year survival rate of approximately 70% after surgical therapy alone. We attempted to clarify preoperative factors that are predictive for poor prognosis after surgery among patients diagnosed with C-IA adenocarcinoma of the lung.

METHODS

Between 1994 and April 2002, 65 patients with C-IA adenocarcinoma of the lung underwent lobectomy + hilar and mediastinal node dissection. The chest computed tomography (CT) imaging and clinicopathologic records of the patients were examined. Tumors were subtyped into solid type or nonsolid type categories according to the component of ground glass opacity assessed by CT. Age, sex, serum carcinoembryonic antigen (CEA) level, histologic subtype (replacing versus nonreplacing), and tumor size were also analyzed.

RESULTS

Solid type on CT and high serum CEA level (>or=4.0 ng/mL) were prognostic factors for poor outcome in univariate analyses (p < 0.05). Solid type on CT, high serum CEA level, and larger tumor size (> 20 mm) were significant (p < 0.05) prognostic factors for poor outcome in multivariate analyses. Solid type on CT and high serum CEA level were significant (p < 0.01) risk factors for lymph node involvement in both univariate and multivariate analyses. Furthermore, based on the factors of CT subtype, tumor size, and serum CEA level, the 5-year disease-free survival rate was 20.1% for patients with two of the three factors, and 21.2% even if they were assessed as pN0. Computed tomography subtype was strongly associated with histologic subtype (p < 0.0001).

CONCLUSIONS

Solid type on CT (associated with histologic subtype such as nonreplacing type), tumor size larger than 20 mm, and high serum CEA concentration are important preoperative predictive factors for poor outcome after surgery for patients with C-IA lung adenocarcinoma.

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.

Grade of Stromal Invasion in Small Adenocarcinoma of the Lung

The pathologic features of invasion such as stromal disruption and pleural/vascular involvement have been shown to be of prognostic value in adenocarcinoma. However, the relationship between the degree of invasion, histologic subtype of adenocarcinoma, and prognosis remains unclear. We retrospectively studied 380 peripheral adenocarcinomas of < or = 2.0 cm in diameter with regard to histology and clinical profiles. Their degree of invasive growth was classified into four grades as follows according to the structural deformity and its location in the adenocarcinoma lesion: Grade 0 had a pure bronchioloalveolar growth pattern and no evidence of stromal invasion. Grade 1 had stromal invasion in the area of bronchioloalveolar growth. Grade 2 had stromal invasion localized on the periphery of a fibrotic focus. Grade 3 had stromal invasion into the center of a fibrotic focus. The clinicopathological data were obtained from medical records. The distribution of the histologic grade of invasion was as follows: grade 0 in 85 tumors (22%), grade 1 in 37 (10%), grade 2 in 46 (12%), and grade 3 in 212 (56%). This histologic grade of invasion was closely related to other indicators of tumor spread. Vascular/lymphatic permeation was seen in none of grade 0, in 1 lesion each of grade 1 and grade 2, and 144 (68%) of grade 3. Lymph node metastasis was seen in 57 (27%) lesions of grade 3 but not in grades 0, 1, or 2. The 5-year disease-free survival rates were 100%, 100%, 100%, and 59.6% for tumors with grade 0, grade 1, grade 2, and grade 3 invasion, respectively. Tumors with grade 1 and grade 2 invasion, like tumors with grade 0 invasion (bronchioloalveolar carcinoma), showed an excellent prognosis. Therefore, tumors with grade 1 and grade 2 invasion could be considered "minimally invasive" or "early" adenocarcinomas.