Regional lymph node and stromal immunomorphology in colorectal carcinoma and relation to tumour spread

Large negative lymph nodes - a surrogate for immune activation in rectal cancer patients?

AIM

The size of regional, tumor draining lymph nodes without metastasis (LNneg) found in rectal cancer resection specimens varies and seems to be related to patient survival. Yet, the histopathological features influencing LNneg size in rectal cancer have not been studied in detail. Our pilot study focused on investigating the relationship between lymph node (LN) size and LNneg microarchitecture in rectal cancer (RC) resection specimens.

METHOD

In this retrospective cohort study, resection specimens from 146 RC patients, treated with either surgery alone (n = 29) or neoadjuvant therapy followed by resection (n = 117), were included in the study. Histology of LNnegs was reviewed to establish number of lymphoid follicles and presence of intranodal fat. Longest long axis and area of each LN were measured digitally.

RESULTS

1830 LNnegs were measured. The microarchitecture was analyzed in a subset of 680 LNnegs. 153 (22.5 %) LNnegs contained intranodal fat. After neoadjuvant treatment, presence of intranodal fat was related to smaller LNneg area (median (range) area of LNneg without intranodal fat: 4.51 mm² (0.15-46.89 mm²), with intranodal fat: 3.46 mm² (0.12-27.22 mm²), p = 0.048). A higher number of lymphoid follicles was related to a larger LNneg area in both patient groups (p < 0.001).

CONCLUSION

Our pilot data suggest that in rectal cancer the presence of large regional LNnegs may reflect increased immune activation due to tumor related antigens. Further studies are warranted to investigate whether histologically visible microarchitectural features of LNnegs such as lymphoid follicles translate to particular features in radiological images and hence could potentially help to identify LNneg with more certainty at the time of pre-treatment disease staging.

High lymph node yield is related to microsatellite instability in colon cancer

BACKGROUND

Lymph node (LN) yield in colon cancer resection specimens is an important indicator of treatment quality and has especially in early-stage patients therapeutic implications. However, underlying disease mechanisms, such as microsatellite instability (MSI), may also influence LN yield, as MSI tumors are known to exhibit more prominent lymphocytic antitumor reactions. The aim of the present study was to investigate the association of LN yield, MSI status, and recurrence rate in colon cancer.

METHODS

Clinicopathological data and tumor samples were collected from 332 stage II and III colon cancer patients. DNA was isolated and PCR-based MSI analysis performed. LN yield was defined as "high" when 10 or more LNs were retrieved and "low" in case of fewer than 10 LNs.

RESULTS

Tumors with high LN yield were significantly associated with the MSI phenotype (high LN yield: 26.3% MSI tumors vs low LN yield: 15.1% MSI tumors; P=.01), mainly in stage III disease. Stage II patients with high LN yield had a lower recurrence rate compared with those with low LN yield. Patients with MSI tumors tended to develop fewer recurrences compared with those with MSS tumors, mainly in stage II disease.

CONCLUSIONS

In the present study, high LN yield was associated with MSI tumors, mainly in stage III patients. Besides adequate surgery and pathology, high LN yield is possibly a feature caused by biologic behavior of MSI tumors.

Number and size of lymph nodes recovered from dukes B rectal cancers: correlation with prognosis and histologic antitumor immune response

PURPOSE

In rectal cancer variation in lymph node recovery influences the detection of nodal metastases and prognosis among Dukes B (Stage II) cases. However, the possible prognostic importance of node size and inherent patient/tumor characteristics in determining node recovery has not been studied.

METHODS

We examined 269 Dukes B (Stage II) rectal tumors, with a mean of 12 nodes per case. Primary tumor characteristics were correlated with the number and size of recovered nodes. Clinical follow-up permitted determination of long-term survival.

RESULTS

The five-year survival of 94 Dukes B cases with nine or fewer nodes was 69.4 percent vs. 87.6 percent in 175 cases with ten or more nodes (P = 0.001). Lymph nodes were smaller in patients dying of recurrence; among 130 Dukes B patients whose mean node diameter was <4 mm, survival was 73.3 vs. 88 percent when mean nodal diameter was > or =4 mm. The number and size of recovered nodes was related to patient age, histologic antitumor immune response, and tumor growth pattern. By combining the number and size of nodes, a poor prognosis subgroup of 98 Dukes B patients with relatively few large nodes (no more than 5 measuring > or =4 mm) was identified with a five-year survival of 65.6 percent compared with 89.6 percent for the remaining 158 Dukes B cases (P < 0.0001).

CONCLUSIONS

In Dukes B rectal tumors, the number and size of lymph nodes are related to inherent patient and tumor characteristics and permit the identification of Dukes B cases at increased risk of recurrence. A valid comparison of nodal sampling efficiency between centers necessitates measuring and counting harvested lymph nodes.

Clinicopathologic study of esophageal squamous cell carcinoma confined to the mucosa

The authors studied patients with esophageal squamous cell carcinoma confined to the mucosa (ESCM) with respect to various clinicopathologic factors to investigate the course of invasion of very early-stage esophageal cancers. A total of 74 patients with ESCM were studied. Fifty of these patients had tumor invasion of the basement membrane confined to the lamina propria mucosae (m2 cancer), and 24 patients had tumor invasion of the muscularis mucosa (m3 cancer). All lesions were investigated with regard to clinicopathologic factors such as tumor differentiation, pattern of invasion, endoscopic morphology, and inflammatory response. The patients were divided into groups of 8 patients with positive lymphatic invasion, lymph node involvement, or both (Inv[+] group), and a group of 66 patients with no lymphatic invasion or lymph node involvement (Inv[-] group). The inflammatory response was evaluated on the basis of lymphocyte infiltration at the tumor invasion front and lymphocytic follicles beneath the tumor invasion front. Mean lesion size was significantly greater in the Inv(+) group than in the Inv(-) group (p < 0.05). However, there was no significant difference in the mean area of invasion of the lamina propria mucosae or deeper between the Inv(+) group and Inv(-) group. Patients with m2 cancer had a significantly higher rate of high-degree lymphocytic follicles than those with m3 cancer (p < 0.01). In patients with m2 cancer, the mean area of invasion of the lamina propria mucosae in patients with high-degree lymphocytic follicles was significantly greater than that in patients with low-degree lymphocytic follicles (p < 0.05), whereas there was no significant difference in mean lesion size between patients with high-degree and low-degree lymphocytic follicles. In patients with ESCM, lesion size was an important risk factor for lymphatic invasion and nodal involvement, lymphocytic follicles were prominent beneath the front of relatively broad cancer invasion, and lymphocytic follicles were less common with deeper cancer invasion.

Significado prognóstico das metástases nos linfonodos regionais do adenocarcinoma colo-retal

Trezentos e vinte doentes com adenocarcinoma colo-retal submetidos a ressecção curativa foram estudados com o intuito de verificar, nas peças ressecadas, o comprometimento ou não dos linfonodos, o número dos acometidos e a área ocupada peia neoplásicas. Chamou-se de linfonodos invadidos aqueles com raros focos de células neoplásicas presentes, que não interferiam na estrutura do nodo e de destruídos àqueles que apresentavam sua estrutura em grande parte ou totalmente ocupada pelo tumor. Os linfonodos positivos foram agrupados em subgrupos contendo 1 a 4 e em mais de 4.120 (38,6%) doentes apresentaram linfonodos comprometidos, dos quais 24,2% eram invadidos e 75,8% destruídos. Portadores de linfonodos livres apresentaram sobrevivência de cinco anos de 71,7%; a sobrevivência de doentes com nodos invadidos - 58,6%- foi significantemente maior que a dos com nodos destruídos - 29,7%, mas não diferiu estatisticamente da apresentada pelos portadores de linfonodos livres. Doentes com mais de 4 linfonodos comprometidos sobreviveram significantemente menos (20,0%) que aqueles com 1 a 4 linfonodos acometidos (43,5%). Entre os portadores de linfonodos invadidos a sobrevivência de 5 anos foi a mesma para os com 1 a 4 ou mais de 4 linfonodos invadidos. Isto não aconteceu com portadores de linfonodos destruídos, onde os com 1 a 4 sobreviveram em cerca de 37,7% e os com mais de 4, 13,3%. Faz-se necessário identificar adequadamente a área ocupada pela neoplasia no linfonodo, pois o comportamento biológico do tipo invadido diferiu substancialmente do destruído. O melhor prognóstico dos portadores de linfonodos invadidos pode explicar a sobrevivência aparentemente paradoxal observada em alguns doentes estadiados na classe C de DUKES.

Identification and quantification of subsets of mononuclear inflammatory cells in melanocytic and other human tumors

We used monoclonal antibodies and an indirect immunoperoxidase technique to identify mononuclear inflammatory cells associated with human tumors. The absolute number of the different types of inflammatory cells was assessed by using a point-counting technique. We studied tissues from six primary cutaneous melanomas, six metastatic melanomas, eight melanocytic nevi, 14 breast cancers, seven examples of fibrocystic disease of the breast, 11 lung cancers, and six colon cancers. Virtually all tumors were associated with substantial numbers of T lymphocytes (Leu3a-positive T helper-inducer cells predominating) and macrophages. Primary melanomas contained significantly more T lymphocytes (P less than .002), macrophages (P less than .005), and Langerhans/dendritic cells (P less than .002) than nevi or normal skin and had a higher proportion of T cells than metastatic melanomas (P less than .01). Breast cancers contained more T lymphocytes and macrophages than occur with fibrocystic disease (P less than .0001 and P less than .002, respectively) and more B lymphocytes. Cancers of the lung and colon contained moderate numbers of T lymphocytes and macrophages; however, colon cancers contained a higher proportion of B cells. Leu7-positive NK/K cells were noted in small numbers in all tumors examined.

Importance of tumor pathology and morphology in patients with surgically resected colon cancer. Findings from the Gastrointestinal Tumor Study Group

Previous analyses of findings from the Gastrointestinal Tumor Study Group (GITSG) study GI 6175, a four-arm randomized trial of patients with adjuvant colon cancer, have revealed no efficacy for chemotherapy or immunotherapy, but Dukes' Stage was found to have prognostic significance in both survival and disease-free survival. In this study, the exophytic tumor as primary type, maximal tumor dimension, and degree of differentiation were examined for prognostic importance. In a model simultaneously including treatment effects, significance levels for prognosis in total survival were: Dukes' stage (P less than 0.0001), exophytic tumors (P = 0.05), maximal dimension (P = 0.005), and well versus poor differentiated tumors (P = 0.06). This observation about tumor length, adjusted for stage and morphology, provides evidence that size is prognostic in colonic tumors. In addition, an interaction between tumor morphology and immunotherapy, adjusted for Dukes' stage, was noted. In 100 patients with exophytic tumors, significant survival and disease-free survival benefit (P less than 0.02) from immunotherapy occurred. Tumor morphology is found to be an important prognostic variable and should be carefully considered in the construction of future trials in this disease site.

Lymphocyte migration during the development of regional lymph node anergy in experimental tumor growth

The development of lymph node anergy in Wistar rats to growing Walker carcinoma 256 was studied in vitro using the 51Cr-release cytotoxicity assay. Cell-mediated cytotoxicity to the tumor peaked in draining lymph nodes 11 days after tumor transplantation. By 14 days, the regional lymph node had become anergic to the tumor at a time when cell-mediated cytotoxicity was still increasing in the more distal contralateral lymph node. Lymphocyte migration into resting, cytotoxic, and anergic lymph nodes was analyzed to determine if altered cell migration into the regional lymph node was associated with the development of anergy. Lymphocyte migration was found to be enhanced in both cytotoxic and anergic regional lymph nodes of tumor-bearing animals. It is concluded that lymph node anergy in this experimental tumor system is not related to changes in lymphocyte migration patterns; rather, it is the result of alterations in the microenvironment of the lymph node which prevents the expression of cytotoxic effector cells.

Lymph node reactions to cancer

Histological, histomorphometrical and histochemical data on the response of regional lymph nodes to tumor development, as recorded in experimental and clinical studies, were coordinated and supplemented by recent findings in experimentally induced autochthonous carcinomas in the rat gastrointestinal tract. The attempted correlation led to the definition of several prognostic parameters: 1) The development of germinal centers and the plasmocytic reaction in tumor draining nodes are morphological expressions of active humoral immune responses that may be specifically directed against the tumor. These reactions attain their maximum usually during late stages of tumor development. Their incidence and prognostic significance may vary depending upon the stage and the type of tumor. 2) Sinus histiocytosis is an immunologically nonspecific lymph node response with debatable prognostic significance. 3) Granulomatous sarcoid-like lesions may be understood as signs of an immunologically mediated antitumor response of macrophages activated by T lymphocytes. They are indicative of a favorable prognosis. 4) Paracortical hyperplasia, characterized by an increased population of lymphocytes and eventually immunoblasts, is an expression of an active T-cell reaction. This reaction occurs typically during early stages of experimental tumors. Correspondingly, it is of favorable prognostic significance in human tumors. 5) Lymphocytic depletion and nodular alteration of T-cell areas, with increased histiocytic infiltration, are reactions most often seen in the draining nodes of an advanced tumor. Both seem to coincide with depression of the cell-mediated immune reactivity. The present assessment of the reactive behavior of diverse lymph node compartments may serve as a first pointer to the proposed histologic immunostaging of malignant tumors.

Germinal centre hyperplasia: an unfavourable immune response in recurrent malignant melanoma

A quantitative immunomorphological analysis of actively responding B-(germinal centre) and T-lymphocyte (paracortical) areas in 187 patients with malignant melanoma recurrent in the regional lymph nodes has been made. The results show that tumour involved nodes have significantly increased germinal centre and decreased paracortical response in comparison with uninvolved lymph nodes. Patients treated with surgery alone whose uninvolved nodes had hyperplastic (defined as exceeding the median) germinal centre areas, had significantly shorter survival than those without germinal centre hyperplasia. No association was found between lymph node immunomorphology and survival in BCG treated patients.

Mucinous colorectal carcinoma: immunopathology and prognosis

A total of 519 colorectal carcinomas were examined for the presence or absence of mucinous differentiation by means of microscopical morphometry. Of these, 28% had objectively measurable amounts of mucinous tumour epithelium. Tumours with > 50% mucinous areas (14%) had significantly poorer prognosis than non-mucinous in stages A and C, while mucinous differentiation did not correlate with prognosis in stages B and D. Lymph nodes regional to mucinous tumours had significantly less paracortical response, and those with < 50% mucinous differentiation, significantly less perivascular lymphocyte cuffing at the tumour margins. These lymph node and stromal compartments are putative T-lymphocyte areas, and hence our findings suggest that mucinous tumours are either less stimulatory or perhaps inhibitory of cell-mediated immunity.