Clinical relevance of histologic subtyping in small cell lung cancer

DeePaN: deep patient graph convolutional network integrating clinico-genomic evidence to stratify lung cancers for immunotherapy

Immuno-oncology (IO) therapies have transformed the therapeutic landscape of non-small cell lung cancer (NSCLC). However, patient responses to IO are variable and influenced by a heterogeneous combination of health, immune, and tumor factors. There is a pressing need to discover the distinct NSCLC subgroups that influence response. We have developed a deep patient graph convolutional network, we call "DeePaN", to discover NSCLC complexity across data modalities impacting IO benefit. DeePaN employs high-dimensional data derived from both real-world evidence (RWE)-based electronic health records (EHRs) and genomics across 1937 IO-treated NSCLC patients. DeePaN demonstrated effectiveness to stratify patients into subgroups with significantly different (P-value of 2.2 × 10-11) overall median survival of 20.35 months and 9.42 months post-IO therapy. Significant differences in IO outcome were not seen from multiple non-graph-based unsupervised methods. Furthermore, we demonstrate that patient stratification from DeePaN has the potential to augment the emerging IO biomarker of tumor mutation burden (TMB). Characterization of the subgroups discovered by DeePaN indicates potential to inform IO therapeutic insight, including the enrichment of mutated KRAS and high blood monocyte count in the IO beneficial and IO non-beneficial subgroups, respectively. Our work has proven the concept that graph-based AI is feasible and can effectively integrate high-dimensional genomic and EHR data to meaningfully stratify cancer patients on distinct clinical outcomes, with potential to inform precision oncology.

Well-Differentiated Neuroendocrine Carcinoma of the Lung: A Clinicopathologic and Ultrastructural Study of 10 Cases

The clinico-pathologic characteristics of 10 resected pulmonary tumors, which proved to be well-differentiated neuroendocrine carcinomas (WDNC) on the basis of light microscopic, immunocytochemical, ultrastructural and immunoelectron microscopic investigations, were evaluated. The tumors showed a wide spectrum of histologic features that could be referred to three basic patterns: 1) a carcinoid-like pattern; 2) an organoid pattern characterized by palisading cells at the edge of cellular areas, and 3) a prevalent adenocarcinoma-like pattern. The second pattern was the most distinct even though it often mimicked the small cell/large cell subtype of small cell carcinoma (SCC) owing to its association with marked atypia and poor differentiation. All but one of the patients were males and smokers. The mean age was 58 years. Half of the tumors were centrally located including those showing the adenocarcinoma-like pattern. Disease-free and overall survival and type of tumor dissemination in four patients were similar to those of SCC. Five evaluable patients were alive and disease-free after a mean follow-up of 74 months. Two of these were initially diagnosed as SCC. We conclude that, because of its impact on prognosis, the diagnosis of WDNC appears to be relevant although other factors able to adversely affect the clinical course remain undefined.

Combined SCLC clinical and pathologic characteristics

INTRODUCTION

Despite the well characterized clinical course of 'pure' SCLC, there have not been many data on combined SCLC, ie, tumors, which contain both small-cell and non-small-cell components.

MATERIALS AND METHODS

We analyzed 1628 consecutive cases of lung cancer (1200 NSCLC, 428 SCLC) at our institution over the past decade. We identified 22 patients with C-SCLC. The pathologic and clinical characteristics of these patients were reviewed. Survival analysis was performed and prognostic factors were assessed. These data were compared with the results obtained from our 406 pure SCLC patients who presented during the same time period.

RESULTS

The most common pathology was combined small-cell and large-cell with 16 cases followed by combined small- and squamous-cell carcinoma (3 cases), 2 cases of small-cell and nonspecified NSCLC, and 1 case of small cell and adenocarcinoma. Overall survival was significantly higher in C-SCLC patients compared with pure SCLC (median 15 vs. 10.8 months; P = .035). Surgery was significantly more common in this group of patients (45% vs. 3% in the pure small cell group; P < .0001). No difference in overall survival was observed in patients with C-SCLC and patients with pure SCLC, that did not receive surgery (P = .64).

CONCLUSION

Patients with combined SCLC carry a better prognosis than those with pure small-cell variety and are more likely to undergo surgery.

Extrapulmonary small cell: a novel case of small cell carcinoma of the thyroid gland

Neuroendocrine tumors comprise a large group of malignancies which share unique morphological features and are characterized by the presence of neuroendocrine markers such as synaptophysin, chromogranin-A, and CD56 (N-CAM), ranging from indolent tumors, such as carcinoid tumors, to aggressive tumors, such as small cell carcinoma. The lung is the most common site for primary neuroendocrine tumors. Extrapulmonary primary sites of small cell carcinoma are rare but have been documented arising from various sites including esophagus, stomach, colon and rectum, gallbladder, thymus, salivary gland, ovary, cervix, bladder, prostate, and skin. We present a case of small cell carcinoma arising from the thyroid gland, a site not previously described in the literature. A 59-year-old woman presented with a thyroid mass, which, after resection, showed small cell morphology and positive immunostains for TTF-1, synaptophysin, chromogranin-A, CD56, etc. Five months after diagnosis, she had widely metastatic disease. After a near-complete response to the first chemo-treatment, her disease progressed. Following local radiation and more rounds of chemotherapy, she succumbed to the disease, 15 months after diagnosis. Our patient had no pulmonary lesions at the time of diagnosis to suggest metastasis from the lung. Much like its pulmonary counterparts, this small cell carcinoma of primary thyroid origin displayed an aggressive clinical course and poor outcome. Although it shows early sensitivity to chemotherapy, small cell carcinoma remains a difficult-to-treat cancer with a poor prognosis and can rarely be seen originating in organs outside of the lung.

Small cell carcinoma of the prostate. A morphologic and immunohistochemical study of 95 cases

Small cell carcinoma of prostate is rare, with the literature consisting of case reports and small series. The current work analyzes the morphology and immunohistochemistry of 95 cases of prostatic small cell carcinoma diagnosed at our institution. Specimens included 55 needle biopsies, 27 transurethral resections, 4 radical prostatectomies, and 9 biopsies from metastatic sites (some patients with >1 procedure). Patients ranged in age from 44 to 92 years old (mean: 69 y). Although serum prostate-specific antigen (PSA) in some cases was very high (up to 1896 ng/mL), the median value was only 4.0 ng/mL. Of cases with available information, 33/78 (42%) had a history of usual prostatic adenocarcinoma. The interval between the diagnosis of small cell carcinoma and prior usual prostatic cancer ranged from 1 to 300 months (median 25 mo). Pure small cell carcinoma was seen in 54/95 (57%) of cases with the remaining cases admixed with prostate adenocarcinoma. In cases with adenocarcinoma, there was a sharp demarcation between small cell carcinoma and adenocarcinoma in 20.5% of cases; in the remaining cases there was gradual merging of the 2 components. In mixed cases, small cell carcinoma predominated (median: 80% of the tumor); the Gleason score of the adenocarcinoma was > or =8 in 85% of these cases. In 61 cases (64%), small cell carcinoma was classic "oat cell" morphology with remaining the "intermediate cell" variant. Of the 95 cases: necrosis was seen in 40% (2% to 95% of the tumor); giant bizarre cells in 19%; Indian filing in 21%; rosette formation in 29%; focal vacuolated cytoplasm in 18%; and desmoplasia in 20%. Most (88%) of small cell carcinoma were positive for at least 1 neuroendocrine marker. In the small cell carcinoma component, 14/73 (19%) were positive for PSA, 17/61 (28%) positive for prostein (P501S), and 15/59 (25%) positive for prostate-specific membrane antigen, although often very focally. Stains for thyroid transcription factor-1 were positive in 23/44 (52.3%) cases. In this, the largest study of prostatic small cell carcinoma, we highlight the presence of morphologic features that may result in its underdiagnosis. Other more classic histologic features of small cell carcinoma along with rosettes are critical for its accurate diagnosis. P501S and prostate-specific membrane antigen were better in identifying the prostatic origin of small cell carcinoma than PSA, although the majority (60%) of prostatic small cell carcinomas were negative for all 3 markers.

Small cell lung carcinoma (SCLC): a clinicopathologic study of 100 cases with surgical specimens

Separation of small cell lung carcinoma (SCLC) from nonsmall cell lung carcinoma (NSCLC) is a critical distinction to be made in the diagnosis of lung cancer. However, the diagnosis of SCLC is most commonly made on small biopsies and cytologic specimens, and practicing pathologists may not be familiar with all its morphologic guises and frequent combination with NSCLC elements, which may be seen in larger specimens. Following the most recent WHO classification of lung tumors and with the hope of identifying prognostic markers, we examined in detail the histology of 100 surgical biopsies or resections with a diagnosis of SCLC from the AFIP and pathology panel of the International Association for the Study of Lung Cancer (IASLC). Multiple clinical and histologic features were studied by Kaplan-Meier analysis. Neuroendocrine architectural patterns, including nested and trabecular growth, with peripheral palisading and rosette formation were common in SCLC. Necrosis and apoptotic debris was prominent in all cases, but crush artifact was infrequent. Cell size in surgical biopsy specimens appears larger than in bronchoscopic biopsy specimens and occasional cells may show prominent nucleoli and vesicular nuclear chromatin, but this does not preclude the diagnosis of SCLC. A high percentage of cases (28%) showed combinations with NSCLC, with large cell carcinoma the most common, followed by adenocarcinoma and squamous cell carcinoma. Because of the frequency of a few scattered large cells in SCLC, we arbitrarily recommend that at least 10% of the tumor show large cell carcinoma before subclassification as combined SC/LC. However, combined SCLC is easily recognized if the additional component consists of other NSCLC subtypes such as adenocarcinoma or squamous cell carcinoma, so no percentage requirement is needed. Stage remained the only predictor of prognosis.

Pathology of lung cancer

This article reviews current concepts in pathologic classification of lung cancer based on 1999 World Health Organization (WHO)/International Association for the Study of Lung Cancer (IASLC) classification. Preinvasive lesions including squamous dysplasia/carcinoma in situ, atypical adenomatous hyperplasia and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia are discussed in addition to current concepts of bronchioloalveolar carcinoma and neuroendocrine tumors.

A review of cytologic findings in neuroendocrine carcinomas including carcinoid tumors with histologic correlation

BACKGROUND

The nosology of neuroendocrine neoplasia has evolved substantially in recent years. The aim of this study was to review the authors' institutional experience and diagnostic accuracy for cytologic specimens of neuroendocrine carcinoma (NEC) and to identify features most suggestive of neuroendocrine differentiation.

METHODS

The cytologic and histologic findings of 29 archival NEC in which cytology preceded biopsy or resection were compared. The study was comprised of 6 carcinoid tumors, 3 atypical carcinoid tumors, 17 high grade NEC (5 small cell, 9 large cell, and 3 mixed small/large cell), and 3 combined NEC/nonneuroendocrine carcinomas. Cytologic material was derived from 21 fine-needle aspirates (FNA), 6 bronchial brushing/washings, and 2 gastrointestinal tract brushings.

RESULTS

Of the 29 cases, the correct cytologic diagnosis was rendered in 11. Two cases were identified as NEC but were graded incorrectly. The remaining 16 cases were interpreted as nonsmall cell carcinoma (8 cases); diagnostic or suspicious of carcinoma, not otherwise specified (7 cases); and atypical, indeterminate for malignancy (1 case). On review, neuroendocrine features were identified in 14 of the latter 16 cases.

CONCLUSIONS

The cytologic diagnosis of NEC, both high and low grade, can be difficult. Because of acinus-like formations and columnar cell shapes, low grade NEC may be mistaken for adenocarcinoma. Small cell carcinomas, especially in bronchial brush and wash preparations, may be difficult to classify beyond malignant. Large cell NEC may be confused with nonneuroendocrine carcinomas because of abundant cytoplasm and nucleoli. Attention to the presence of loose cell aggregates in a background of singly dispersed cells; feathery patterns created by tumor cells clinging to capillaries; rosette formations; delicate, granular cytoplasm; inconspicuous nucleoli; molding in high grade tumors; and, most important, speckled or dusty chromatin patterns are useful in identifying neuroendocrine differentiation in cytologic specimens.

Localization of small-cell lung cancer xenografts with iodine-125-, indium-111-, and rhenium-188-somatostatin analogs

We examined the potential of radiolabeled somatostatin analogs, 125I-Tyr-3-octreotide (125I-octreotide), (111)In-DTPA(diethylenetriaminepentaacetatic acid)-D-Phe-1-octreotide (111In-octreotide), and 188Re-octreotide for targeting small-cell lung cancer (SCLC) in a mouse model. Tyr-3-octreotide was labeled with 125I by the chloramine T method, and (111)In-octreotide was obtained as a kit, while 188Re was eluted from a 188W/188Re generator, and octreotide was directly labeled with 188Re by reducing disulfide bonds. The 125I-, 111In-, and 188Re-octreotides were injected i.v. into athymic mice bearing NCI-H69 tumors, and the biodistributions were determined at 15 min, and 2, 4, 8, and 24 h. Tumor uptakes were 0.5+/-0.2, 0.3+/-0.1, 0.3+/-0.1 %ID/g, and tumor-to-blood ratios were 1.8, 11.9, 1.2 at 8 h for 125I-, 111In-, and 188Re-octreotides, respectively. Accumulations of 111In-octreotide in normal tissues were lower than those of 125I- and 188Re-octreotides. 188Re-octreotide can be used to localize SCLC lesions as efficiently as radioiodinated octreotide. However, 111In-octreotide was the most suitable agent to obtain high tumor-to-normal tissue contrast for localizing SCLC.

Histologic changes in small cell lung carcinoma after treatment

BACKGROUND

Small cell lung carcinoma (SCLC) has been divided into three subtypes: pure SCLC, mixed small cell/large cell carcinoma (mixed SC/LC), and combined SCLC. Patients with mixed SC/LC show a worse prognosis than those with pure SCLC.

METHODS

Persistence of histologic subtype in SCLC in the primary sites during the course of treatment or in the different organs at autopsy was examined. For this purpose, biopsy or cytologic specimens before chemotherapy, and autopsy specimens from 175 patients with SCLC were reviewed. They included 147 (84%) men and 28 (16%) women with an age range of 29-83 (median, 65) years.

RESULTS

The frequency of mixed SC/LC in the primary sites was statistically higher in autopsy (14.3%) than that in biopsy or cytology specimens (8.6%) (P < 0.05). At autopsy, involved organs were categorized into two groups according to frequency of appearance of mixed SC/LC, i.e., a higher frequency group, including the liver (31 of 85; 36.4%), adrenal gland (15 of 56; 26.8%), brain (6 of 9; 66.7%), and extrathoracic lymph nodes (17 of 59; 28.8%) and a lower frequency group, including the lung (metastatic sites) (12 of 102; 11.8%), pleura (8 of 74; 10.8%), and intrathoracic lymph nodes (12 of 94; 12.8%). The difference in frequency between these two groups was statistically significant (P < 0.05).

CONCLUSIONS

These findings suggest that primary pure SCLC can progress to mixed SC/LC with an increased potential for distant metastasis.

Evolution of chromosomal alterations and biologic features in two small cell lung carcinoma cell lines established from one patient during the course of the disease

Two small cell lung cancer (SCLC) cell lines were established from metastases of a patient during the course of the disease. SCLC 74A was derived from biopsy material obtained at the time of diagnosis and SCLC 74B was from a biopsy specimen of a relapsed tumor obtained after treatment. A transition occurred from SCLC 74A, an intermediate form with 5% large cells to SCLC 74B, a standard mixed form with 20% of large cells, with a decrease in neuroendocrine markers and a substantial increase in P-glycoprotein, a multidrug resistance marker. For both cell lines, R-banding and FISH indicated a del(1)(p35pter) also found in other neural-crest-derived tumors, the loss of regions with suspected tumor suppressor genes at 3p, 5q, and 17p, and a recurrent translocation of the 6q24-6qter region to 10p14. Further genetic modifications in SCLC 74B affected chromosomes 2, 3, 5, 10, 11, 14, and 15. The main observations were a der(2)t(2;5)(p16;q?); a der(3;11)(q10;p10) in SCLC 74A which became der(3;14)(q10;p10) and der(11;14)(p10;q10) in SCLC 74B; and the insertion of the 5q13-5q31 region in the der(10)t(6;10). The finding of the same structural abnormalities in both cell lines suggests a monoclonal origin for both metastases. Hypotetraploid cells were in the same proportion as large cells whose number was a characteristic feature of each cell line. They possessed twice the same chromosomal alterations observed in the hypodiploid cells. This suggests a permanent process of tetraploidization.

Nuclear/cytoplasmic ratio correlates strongly with survival in non-disseminated neuroendocrine carcinoma of the lung

In order to verify whether quantitative morphological indices of neuroendocrine carcinoma of the lung may help to predict survival, 47 biopsies (from 37 males and 10 females; 16-82 years of age) were studied by light microscopy. Areal fractions of nuclei, cytoplasm, stroma, and blood vessels were determined using a standard point counting method. The counts were made in six non-coincident microscopic fields in each case, and the areal fractions of nuclei, of the entire tumour cell, stroma, blood vessels and the nuclear/cytoplasmic ratio were computed. In a multivariate linear regression analysis, survival in months after biopsy was considered the dependent variable of age and of all morphometric parameters listed above. The significance level was set at 5%. For all patients (disregarding staging) survival was negatively correlated (P < 0.001, multiple r = 0.5435) with age and nuclear/cytoplasmic ratio. When only patients with disease confined to the thorax (stages I, II and III) were taken into account, the accuracy of the function predicting survival increased considerably (P = 0.004, multiple r = 0.7957). The use of simple stereological methods, therefore, proved to be of value in predicting survival in patients with neuroendocrine carcinomas of the lung.

Detection of large cell component in small cell lung carcinoma by combined cytologic and histologic examinations and its clinical implication

BACKGROUND

In the classification recently proposed by the Pathology Committee of International Association for the Study of Lung Cancer, small cell lung carcinoma (SCLC) was divided into three subtypes: pure SCLC, mixed small cell/large cell carcinoma (mixed SC/LC), and combined SCLC.

METHODS

To examine the clinical utility of this classification, histologic specimens, cytologic specimens obtained by brushing or fine-needle aspiration, and sputum cytologic specimens from 430 patients with SCLC were reviewed.

RESULTS

When the subtype of SCLC was determined from the biopsy specimen, cytologic specimen obtained by brushing or fine-needle aspiration, and sputum cytologic specimen, the frequency of mixed SC/LC was 25 of 299 (8.4%), 75 of 400 (18.8%), and 8 of 232 (3.4%), respectively. Whatever the diagnostic method, patients with mixed SC/LC showed a poorer response to treatment and worse prognosis than those with pure SCLC: a median survival of 144 days versus 285 days when classified with the use of biopsy specimens; 160 days versus 275 days with cytologic specimens obtained by brushing or fine-needle aspiration; and 47 days versus 259 days with sputum cytologic specimens, respectively.

CONCLUSIONS

These findings showed that mixed SC/LC should be separated from pure SCLC as a distinctive group and that cytologic studies of specimens obtained by brushing or fine-needle aspiration were sensitive and useful procedures for this purpose.

An immunohistochemical and ultrastructural study of case of small-cell neuroendocrine carcinoma in the ampullary region of the duodenum

One case of small-cell neuroendocrine carcinoma in the ampullary region of the duodenum is reported. The histological appearance of the tumor was identical to pulmonary small-cell carcinoma. Neuroendocrine differentiation was demonstrated immunohistochemically by positive immunoreaction for neuron specific enolase, Leu-7 and chromogranin, and ultrastructurally by the presence of scanty dense-core neurosecretory type granules. Small-cell neuroendocrine carcinoma in the ampulla of Vater is extremely rare. To our knowledge, this is the sixth reported case.

Prognostic significance of histopathologic subtype and stage in small cell lung cancer

A study of 149 light microscopic tissue slides from 147 patients with recorded initial diagnoses of small cell lung cancer (SCLC) (114 cases) and undifferentiated carcinoma (35 cases) was undertaken to test the reproducibility and prognostic impact of a new histopathologic subclassification of SCLC proposed by the Pathology Panel of the International Association for the Study of Lung Cancer (IASLC). This study was further designed to test the impact of clinical stage, age, sex, and race on survival. The tissue slides were blindly reclassified as SCLC or non-SCLC by a panel of five pathologists with no knowledge of the initial diagnosis. The SCLCs were divided into the three subtypes outlined by the IASLC pathology panel: small (classic or pure), mixed (small cell/large cell), and combined (small cell/squamous carcinoma or small cell/adenocarcinoma). Small cell lung cancer was clinically staged as local, regional, or distant. Consensus diagnosis (defined as agreement by at least three of the five pathologists) was achieved in 144 (96.6%) of the 149 cases. Of these 144 cases, 124 were reclassified as SCLC (115 [92.8%] small, five [4.0%] mixed, and four [3.2%] combined) and 20 were classified as non-SCLC. The median lengths of survival for the small, mixed, and combined subtypes were 225, 1,110, and 203 days, respectively (P = .025). Adequate staging data were available in 123 of the 124 SCLC cases. Of the 123 SCLC cases, 27 (21.9%) were local, 22 (17.9%) were regional, and 74 (60.2%) were distant stage. The median lengths of survival for the local, regional, and distant stages were 428, 251, and 111 days, respectively. This association was highly significant (P = .0001). We conclude that stage is the major determinant of survival in SCLC. Mixed subtypes had significantly longer survival times than the small or combined subtypes (P = .025). Survival times were longer for women than for men, and the survival time difference between men and women was significant (P = .0028). We found no significant differences in survival according to age or race.

Etoposide versus methotrexate in small cell bronchial carcinoma. A randomized study of two types of four-drug chemotherapy regimens

Seventy-nine patients with small bronchial carcinoma randomly received cyclophosphamide, doxorubicin, vincristine, and methotrexate, alternating after four cycles with cyclophosphamide, lomustine, vincristine and methotrexate or the same with replacement of methotrexate by etoposide in lomustine cycles. Patients with limited disease received radiotherapy with 40 Gy. In 34 patients with extensive disease the total response in the groups with and without etoposide was 89% and 69% and the median survival 10.9 and 8.2 months respectively. In 45 patients with limited disease, the complete remission rates in the groups with and without etoposide were 57% and 67%, partial remission rates 38% and 25%, and the median survival times 12.3 and 17.8 months respectively. The disease-free survival exceeding 5 years in the respective groups was 4.2% and 14.3%. A slightly better response in extensive disease and a tendency to better long-term survival in limited disease was noted but the price was increased toxicity in the latter group.

Neuroendocrine differentiation in lung tumours

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