Studies concerning the regional lymph node in cancer. IV. Tumor inhibition by regional lymph node cells

A Short History of Bernard Fisher's Contributions to Randomized Clinical Trials

Dr. Bernard Fisher (1918-2019) was an early proponent of evidence-based medicine using the mechanism of prospective, multicenter, randomized clinical trials to test biological and clinical hypotheses. In this article, I trace how his early scientific work in striving to understand the nature of cancer metastasis through animal experiments led to a new, testable, clinical hypothesis: that surgery to remove only the tumor and a small amount of tissue around it was as effective as the more disfiguring operations that were then the standard treatment. Fisher's work with the National Surgical Adjuvant Breast and Bowel Project (NSABP) using large, randomized clinical trials to demonstrate the veracity of this hypothesis led to a new paradigm in which the emphasis was placed on how systemic therapies used at an early stage of disease could effectively eradicate breast cancer for many patients. This new therapeutic approach led to the successful development of new treatments, many of which are widely used today. Ultimately, the new paradigm led to successfully preventing breast cancer in women who were at high risk for the disease but who had not yet been diagnosed with the disease. Throughout his entire career, Fisher championed the use of large prospective, randomized clinical trials despite criticism from many in the medical community who strongly criticized his use of randomization as a mechanism for testing clinical hypotheses. The approach he and the NSABP employed is still considered to be the highest standard of evidence in conducting clinical studies.

Biology and surgical management of breast cancer

The surgical treatment of breast cancer has been a source of controversy. The controversy arises from the differences in physicians' philosophies regarding the biology of breast carcinoma. Traditionally, surgeons have emphasized the potential therapeutic value of regional lymph node dissection, maintaining that adequate loco-regional treatment is of prime concern in patients with localized tumors. On the other hand, medical oncologists have always stressed the systemic nature of cancer. However, breast cancer is a very heterogeneous disease with an enormous range of different biologic characteristics, and new information is continually becoming available on the natural history of breast cancer. Therefore, we should seek a more rational theory based on the clinical evidence which can explain the biologic characteristics of breast cancer. We have proposed a new spectrum hypothesis as follows: (a)tumor cells traverse lymphatics to lymph nodes by direct extension, and there is an orderly pattern in the early stage of lymph node metastases; (b)regional lymph nodes are able to trap tumor cells but are ineffective or incomplete barriers to tumor cell spread; (c)regional lymph nodes have biologic importance, and a positive lymph node is an indicator of a host-tumor relationship that correlates with the subsequent appearance of distant disease; (d)lymphatic and hematogenous dissemination occur not serially, but in a parallel fashion; (e)many palpable invasive breast cancers are a systemic disease, but non-invasive or minimally invasive breast cancers are likely to be a local disease; (f)early detection and treatment of in-breast cancer improves survival, but variations in regional therapy are unlikely to have a major influence on survival.

Functional expression of CD11a on CD8+ cells is suppressed in regional lymph nodes with cancer involvement in patients with gastrointestinal carcinoma

BACKGROUND

To evaluate the immunologic activity of regional lymph nodes, the phenotype of lymphocytes and the functional expression of cell adhesion molecules (CAMs) on lymph node lymphocytes (LNL-: uninvolved, LNL+: involved) were investigated in patients with gastrointestinal carcinoma.

METHODS

The lymphocyte subpopulation and the expression of CD11a, CD44, and CD29 on CD4+ and CD8+ cells in peripheral blood lymphocytes (PBL), LNL- and LNL+ derived from 37 patients with gastrointestinal carcinoma were studied. In addition, the adherence of CD8+ cells to ICAM-1 which reflects the adhesive function of CD11a, was examined, and changes in this adherence were studied by experimental coculture with cancer cells (DLD-1).

RESULTS

Although there were no differences in the overall proportion of T cells between the groups, CD8+ cells and CD16+ cells were considerably diminished in LNL+. The expression of CD11a and CD29 on CD4+ and CD8+ cells was significantly lower in LNL than in PBL, whereas the expression of CD44 showed no significant differences. The expression levels of these CAMs were almost the same in LNL- and LNL+. Only CD11a expression on CD8+ cells in LNL+ was significantly lower than that in LNL- (P < 0.005). The adherence of CD8+ cells in LNL+ to ICAM-1 was lower than that in PBL and LNL-, and was extremely enhanced by experimental coculture with cancer cells (DLD-1).

CONCLUSIONS

These data indicate that the functional expression of CD11a (LFA-1) on CD8+ T cells is suppressed in cancer-involved regional lymph nodes in patients with gastrointestinal carcinoma.

Effect of sizofiran on regional lymph nodes in patients with head and neck cancer

The immunomodulating effects of preoperative sizofiran (SPG) administration on regional lymph nodes were studied in patients with stage III or IV head and neck cancer, by comparing the immunofunction of peripheral blood. The regional lymph nodes were dissected surgically, and freshly obtained mononuclear cells were studied to investigate the interleukin 2 (IL-2) production, the LAK and NK activities, and the quantitative analysis of the surface phenotype of the mononuclear cells. The results indicated that SPG enhanced immunological activities in the regional lymph nodes, as shown by increased IL-2 production and cytotoxic activities of the effector cells (NK, LAK), and increased helper T lymphocytes (CD4+) in the tumor-uninvolved lymph nodes. The immunofunction following SPG administration was attenuated, but was still augmented in the regional lymph nodes with metastases. Therefore, SPG was found to be a biologic response modifier to enhance the immunofunctions of the regional lymph node in patients with head and neck cancer.

Clinical management of the regional lymph node

Appropriate clinical management of the regional lymph node remains controversial. This article briefly reviews the anatomy and physiology of the lymphatic system, pathophysiology of lymphatic metastases, and some guidelines and rationale for clinical management.

Elective lymph node dissection for melanoma

The role of elective lymph node dissection (ELND) in the management of primary melanoma of the skin is a controversial subject. Some authorities consider the indications for this procedure to be broad, whereas others rarely recommend ELND. Voluminous literature reflects these divergent opinions. Unfortunately, this can be confusing for the practitioner advising a patient with melanoma. We review arguments for and against ELND and review some of the most important studies of the effects of ELND on survival. We attempt to elucidate the sources of controversy inherent in these survival studies. Criteria for the selection of appropriate candidates for ELND are discussed. ELND with hyperthermic limb perfusion is also briefly reviewed.

Augmentation of antitumor immunity in regional lymph nodes by local immunotherapy

We have previously reported that the antitumor effect of OK-432, a streptococcal preparation, is markedly augmented when injected intratumorally together with fibrinogen (OK-432/fbg) [1]. In order to elucidate the effects of this immunotherapy on regional lymph nodes (RLN), we carried out both morphological and functional analyses of the RLN from colonic cancer patients treated with OK-432/fbg. Computer-aided morphometry revealed that the maximal cross-sectional areas and the broadest diameters of the RLN were significantly greater (p < 0.01) in patients who had undergone local immunotherapy than in patients who had not. The component structures of RLN, such as sinus, follicle and paracortex, were all enlarged in the OK-432/fbg-treated patients, and necrosis of metastatic tumors was observed. RLN lymphocytes recovered from OK-432/fbg treated patients showed elevated reactivity to phytohemagglutinin (PHA) and the stimulation index was clearly higher than that of control patients. Flow cytometric analysis revealed a predominance of T-cells, especially CD4 subsets, and higher positivity for both CD25 and HLA-DR. Furthermore, RLN lymphocytes killed more effectively K562 and Daudi cells in the patients who had had immunotherapy. These results suggest that the effect of local immunotherapy with OK-432/fbg is not restricted to the site of injection but extends to the lymph nodes, and contributes to tumor regression through the augmentation of cellular immunity.

Prognostic significance of regional lymph node reaction after curative resection of advanced gastric cancer

The prognosis of patients with advanced gastric cancer who undergo curative resection is still unsatisfactory. The relationship between prognosis and various factors such as stage, lymph node metastasis, serosal invasion and regional lymph node reaction (follicular hyperplasia and sinus histiocytosis) was evaluated. Of the factors studied, the only one that correlated well with survival was sinus histiocytosis. Lymph node metastasis was related weakly to prognosis. No correlation between prognosis and stage, serosal invasion or follicular hyperplasia was observed. Sinus histiocytosis may represent the morphological tumour-host immune reaction. Lymph node metastases or histological types were not related to regional lymph node reaction. These results suggest that sinus histiocytosis could be a useful prognostic factor for gastric cancer. Intensive postoperative follow-up for recurrence may be necessary even for patients with low-grade sinus histiocytosis in whom curative surgery is attempted.

An assessment of neck node immunoreactivity in head and neck cancer

Current conventional forms of cancer treatment represent non-specific modalities that destroy not only cancerous but also non-cancerous tissue in an effort to totally eradicate the neoplasm. It was unknown in head and neck cancer whether a more specific form of treatment, as it relates to neck nodal disease, was advisable. The purpose of this investigation was to study the cervical node immunoreactivity in head and neck cancer patients as a means of determining their immunologic capabilities and thus provide information about the merits of specific vs. non-specific cancer treatment. The results demonstrated that lymphocytes arising from cervical nodes caused alterations in the tumor growth. There appeared to be no particular difference in immunoreactivity of lymphocytes arising from nodes located in different areas of the neck. The regional immune system of neck nodes in the head and neck cancer patient appears to be capable of mounting an immune response irrespective of the patient's tumor status. Usual measures of systemic immunocompetence failed to identify any patients with advanced stage disease and showed little correlation with the regional immunoreactivity. The regional nodal immunoreactivity also did not correlate with the size or the numbers of metastatic neck nodes. The results demonstrate that cervical neck nodes are capable of mounting an immune response to head and neck cancer and are not mere passive filters that are periodically involved with tumor emboli. These results support the need for the development of reliable treatments which are directed at tumor tissue only.

Proliferative patterns of lymphocytes in lymph nodes during tumour development: involvement of T and B cell areas

DNA-synthetizing lymphocytes were identified in the lymph nodes regional and more distal to the site of developing P-815 tumours by incorporation of [3H]-thymidine followed by autoradiography of lymph node sections. It appeared that not only T but also B cell areas of draining and to a lesser extent of distal lymph nodes were stimulated by the growing tumour. This result was unexpected since neither humoral nor tumour cell-bound antibody could be identified so far as a functional correlate of B cell stimulation. In general the proliferative response of lymphocytes followed a biphasic pattern with an early peak of reactivity on days 2-3 and a second peak around day 12-15 after tumour cell inoculation. In the draining (axillary) lymph node the second peak of reactivity was suppressed, possibly as a consequence of metastatic tumour cells in this node when tumour cells were inoculated in the flank. The pattern of lymphocyte stimulation revealed larger individual variations after tumour cell inoculation in the flank than the foot pad. These results were associated with a slower and less regular drainage of carbon particles from the flank to the axillary and exceptionally the brachial lymph node than from the foot pad to the popliteal node after injection of India ink.

Pathology of primary tumors and axillary lymph nodes in British and Japanese women with breast cancer

Histopathologic features of the primary tumor and axillary lymph nodes from 97 consecutive patients with breast cancer from Japan were compared with those from 164 patients from England. Between the two groups, there were statistically significant differences in the morphology of the primary tumors regarding nuclear grade and patterns of tumor infiltration. In axillary lymph nodes, sinus histiocytosis was much more common in Japanese cases than in British cases, and was related to a diminished frequency of axillary node metastases. Germinal centers were also more common in the nodes of Japanese patients and were similarly associated with diminished frequency of metastases.

The preoperative detection of axillary lymph node metastases in breast cancer by isotope imaging

Axillary lymphoscintigraphy using 99Tcm-labelled liposomes was carried out in 40 patients with breast cancer as a part of pretreatment staging in an attempt to improve the accuracy of axillary evaluation. Patients were injected interstitially in the periareolar region of each breast with 250–300 μCi of 99Tcm-labelled liposomes. Subsequently the patients were imaged with a gamma-camera using computerized data processing. Interpretation of images was based on prior experimental data; a diminished uptake of isotope by the primary regional lymph node (PRLN) and the group of axillary regional lymph nodes (RLN) draining the tumour, when compared to the control side, was considered to be abnormal and to suggest node metastases. An equal or enhanced uptake by the PRLN or RLN draining the tumour, when compared to the control side, was considered normal, indicating an absence of lymph node metastases. Eighteen patients (45 per cent) had abnormal scans and 14 patients (35 per cent) had normal scans. Eight patients (20 per cent) had technically unsatisfactory images where axillary nodes could not be identified. Twenty-two patients of the 32 with evaluable scans had correlation of preoperative images with postsurgical axillary lymph node histopathology. One patient out of 12 with an abnormal scan had normal lymph nodes on serial sectioning, and 2 patients out of 10 with normal scans had lymph node metastases. Eight of the 32 patients (25 per cent) with evaluable images had enhanced uptake of isotope by the PRLN and RLN draining the tumour. In 3 of these cases a marked reactive hyperplasia only was shown on histopathological examination, in 2 cases the reactive hyperplasia was associated with lymph node metastases, accounting for the 2 false negative interpretations. This preliminary study suggests that axillary lymphoscintigraphy may be of value in preoperative staging in breast cancer. Long term studies are needed to evaluate the prognostic potential of such a test as a measure of macrophage function. Further studies, by blind replication, are required to evaluate the accuracy of axillary lymph node imaging.

Effect of regional or distant lymph node removal and of splenectomy on immunologic responses in Ehrlich tumor-bearing mice

To study the role of regional (RLN) and distant (DLN) lymph nodes and of the spleen in the regulation of tumor immunity, we monitored tumor growth in mice subjected to lymph node removal or splenectomy. We found that tumor growth was facilitated when RLN were removed before or soon after tumor inoculation and that RLN removal after extirpation of the immunizing tumor decreased the host resistance to a subsequent challenge. When splenectomy preceded tumor inoculation, tumor growth was not affected, however, marked growth inhibition was observed when splenectomy was performed 5 days after tumor inoculation. Furthermore, splenectomy combined with extirpation of the immunizing tumor increased the host resistance to a subsequent challenge. We conclude from these studies that RLN or the spleen may be of immunologic importance in the host's tumor resistance.

Bronchogenic carcinoma: survival after surgical treatment according to stage, histologic type and immunomorphologic changes in regional lymph nodes

The survival rates of 90 patients who underwent operation for bronchogenic carcinoma were analyzed statistically according to sex, age, tumor stage and histologic type, types of surgical procedures (lobectomy or pneumonectomy), and to immunomorphologic parameters of immunologic activity in peribronchial and hilar lymph nodes. The Stage I group survived significantly longer than did the Stage II and III groups, the lobectomized patients survived significantly longer than the pneumonectomized patients. The absence or presence of lymph node metastases was one of the major determinants of survival. The mean values (percent of total node cut surface) of lymph node sinus histiocytosis and of paracortical area could be correlated directly to survival in each of the histologic tumor-type groups, while the development of follicular cortex and germinal centers correlated inversely with survival. Increased survival might be associated with changes concomitant with immune reactivity in lymph node T-cell areas and with the sinus histiocytosis pattern, the latter representing probably a tumor--host reaction of the delayed hypersensitivity type. By contrast, increased activity of lymph node B-cell areas tended to correlate with poor prognosis of lung cancer patients. Moreover, patterns showing germinal center hyperplasia were statistically associated with lymph node neoplastic invasion, while the pattern with sinus histiocytosis and expanded paracortical areas was statistically associated with tumor-free lymph nodes.

Surgical management of regional lymph nodes in cutaneous melanoma

The initial evaluation of melanoma patients should include an assessment of the regional lymph nodes for metastatic disease. Clinical palpation of the nodes is an important but relatively crude index of metastatic melanoma. In clinically normal nodes, the risk of microscopic metastatic melanoma can be predicted by such prognostic factors as thickness, ulceration, and anatomic location of the melanoma. Other prognostic factors, including the level of invasion and growth pattern (nodular and superficial spreading) provided no additional predictive information after these dominant factors were accounted for. Stage I patients with intermediate thickness melanoma (0.76-4.00 mm) have an improved survival rate with elective lymphadenectomy, while those with thin (less than 0.76 mm) and thick (greater than or equal to 4.00 mm) melanomas do not benefit from elective node dissection. Stage II melanoma patients with documented nodal metastases have relatively poor survival rates because of a high risk for distant microscopic metastases. A surgical strategy for deciding about the timing, the extent, and the treatment goals of regional node dissection in melanoma patients is reviewed.

Reliability of axillary lymph node scintiphotography in suspected carcinoma of the breast

The ability of axillary lymph nodes to take up 99Tcm-labelled antimony sulphide colloid in suspected carcinoma of the breast was investigated in 111 consecutive patients. Eight out of 17 patients with histologically confirmed carcinoma of the breast had a low colloid uptake on the affected side, i.e. a positive scintiphoto. Eighty-two out of 94 patients with benign breast disease had an equal colloid uptake on the two sides or increased uptake on the symptomatic side, i.e. a negative scintiphoto. The reliability of the test is low and the test can neither be recommended for screening to select patients for further investigations nor as a routine examination.

Diagnosis of malignant breast disease by axillary lymphoscintigraphy: a preliminary report

The ability of regional lymph nodes to take up 99Tcm-labelled antimony sulphide colloid from the breast tissue was studied in 50 patients with mammary symptoms by gamma-camera scanning. Thirteen out of 14 patients with histologically confirmed carcinoma of the breast had a depressed uptake of labelled colloid in ipsilateral nodes, i.e. a positive scan. Twenty-nine out of 32 patients with benign breast disease had a negative scan. The method promises to aid both the precise diagnosis of breast disease and the definition of the extent of mammary cancer.

A study of technetium-labelled sulphide colloid uptake by regional lymph nodes draining a tumour-bearing area

With appropriate controls, experimental groups of inbred C3H mice bearing a syngeneic mammary carcinoma challenge in their right rear footpads were injected in both rear footpads with 99TcmASC. Mice were sacrificed 15 and 90 min after the labelled colloid injection. Popliteal and sacral lymph nodes were weighed and counted in a well scintillation counter. A marked inhibition of labelled colloid uptake was demonstrated in regional lymph nodes draining a tumour-bearing area. Rabbits bearing VX2 carcinoma in a forelimb received 99TcmASC into each front footpad. Depression of labelled colloid uptake by regional lymph nodes draining tumour was evident on gamma-camera scanning.

Immune response of the draining and distal lymph nodes during the progressive grwoth of a chemically-induced transplantable rat hepatoma

The immunological and histological changes occurring in the lymph node draining the site of a progressively growing intramuscular tumour (D192A) implant were monitored during a 4-week time course. Cell-mediated cytotoxicity against hepatoma-D192A and 15-day rat embryo cell targets, was detected with cells derived from the draining "lumbar" lymph node 4 days after tumour implantation and persisted up to the 2nd week of tumour growth, decreasing rapidly during the 3rd week. The observed lymph-node anergy demonstrated in cytotoxicity tests correlated with the histological findings, in that an initial marked paracortical (T-dependent) response also declined towards the end of the 3rd week of tumour growth. The B-dependent cortex showed active lymphocyte follicles in the 2nd week of the time course, and plasma-cell production continued until the experiment was terminated. These changes were shown to occur with the progressive increase in lymph-node mass. Serum antibody specific for the developing tumour was detected during the latter stages of tumour growth. The immunological and histological changes displayed were out of phase with those shown by the draining lymph node.

Biostatistical basis of elective node dissection for malignant melanoma

During the years 1954 through 1964, 259 individuals with primary malignant melanoma had an elective node dissection. Microscopic metastases were found in 15% of these patients. The presence of only a microscopic focus of involvement gave a 10-year cure rate of 67%; metastasis larger than a microscopic focus in a single node, 50%; and more than one node, 15%. One hundred forty-five individuals were treated by wide excision alone with 18% subsequently requiring a therapeutic lymphadenectomy with a ten-year cure of only 6%. A prospective study was then initiated which was concerned with efficacy of selection of patients for elective node dissection. Clark's level of invasion was determined for 258 patients treated since January 1972. The depth of invasion of the primary lesion was found to correlate directly with the absence of lymph node metastases, extent of nodal involvement, and rate of recurrence. It is concluded that the concept of elective node dissection is valid.

Histopathological study of regional lymph nodes in osteosarcoma

This paper presents the histological appearance of the lymph nodes in cases of osteogenic sarcoma of the limb bones. The nodes were studied for the degree of sinus histiocytosis. Cases with no sinus histiocytosis showed a poor prognosis while cases with moderate to marked sinus histiocytosis showed a better rate of survival. Since the regional lymph nodes play an important part in the immunological process, preservation of regional nodes is suggested.

Problems relating to immunoselection of leukemias

Problems relating to immunoselection of neoplastic, in particular leukemic, cell lines are reviewed. Since there is ample evidence that specific immune reactions of the host against malignant neoplastic cells do occur, it becomes important to consider the effectiveness and the relevance of immunity in suppression or elimination of neoplastic growth. Emphasis is placed on experimental results obtained in syngeneic tumor-host combinations, because they more closely resemble the situation of spontaneous tumorigenesis or leukemogenesis than xenogeneic or allogeneic model systems. Studies of types of neoplasia observed in cases of human immunodeficiency syndromes offer an important insight into problems involved in immunoselection of leukemic cell lines: the marked predominance of leukemias and lymphoreticular neoplasias in immunodeficient patients invites speculation on both the mechanisms of leukemogenesis and the relative importance of the immune system in eliminating malignant neoplastic cells.

Immunocompetence, immunosuppression, and human breast cancer. I. An analysis of their relationship by known parameters of cell-mediated immunity in well-defined clinical stages of disease

General immune competence was examined 255 breast cancer patients, including 104 operable, 44 locally advanced/inoperable, and 44 with demonstrable metastatic dissemination, all at the time of diagnosis, as well as 63 disease-free long survivors; this was compared with that of 100 normal controls. The parameters employed were PPD and DNCB skin testing, lymphocyte response to PHA mitogen, E-rosette formation, and lymphocyte number. Significant patients, with only 31% showing optimal and 25% showing minimal levels of immune function, as compared with 70% optimal and 2% minimal function in controls. Immune competence was not affected by metastatic involvement of regional lymph nodes. In patients with early, occult metastatic dissemination (as determined in retrospect), the degree of immune competence was found to be identical to that of patients who did not develop disease dissemination. Remarkably, this early phase of tumor spread is not accompanied by immune impairment, such as is evident in clinically demonstrable metastatic disease and, to a lesser degree, in advanced local and regional disease. Since tumor dissemination preceded impairment of general immunocompetence, it emerges as the cause rather than the result of immunosuppression. Long disease-free survivors, who had postoperative irradiation 5-12 years previously, were shown to have a notably low level of immune competence. Lymphocyte response to PHA stimulation was found to be impaired in the earlier stages of disease, while skin DHR was still well maintained; in advanced disease both parameters tend to correlate as total immunologic impairment ensues. The sequence of immunologic events leading up to immunosuppression with disease progress is discussed.

Studies concerning the regional lymph node in cancer. VIII. Effect of two asynchronous tumor foci on lymph node cell cytotoxicity

Results suggest that cytotoxicity by cells from nodes regional to a primary tumor is unique. While a primary tumor was present, A) cytotoxicity was displayed by cells from lymph nodes (RLNs) to that tumor, B) cells from nonregional lymph nodes regional (NRLNs) possessed lesser cytotoxicity which failed to increase in response to a second tumor focus in an area drained by those nodes, and C) the second focus attenuated cytotoxicity of cells from LNs regional to the primary tumor. Following removal of the primary tumor, cells from RLNs rapidly lost cytotoxicity and with passage of time were unable to regain that function in response to a second tumor focus. In contrast, cells from NRLNs demonstrated increased cytotoxicity at any time following removal of the primary tumor when exposed to a second focus. These observations suggest that nodes regional to a distant metastatic focus may be unable to react to it and thus contribute little to the host response generated by the primary tumor. In addition, since nodes regional to a primary tumor manifest diminished cytotoxicity in the presence of a distant tumor focus, tumor cells gaining access and lodging in those nodes subsequent to the development of other metastatic foci are likely to proliferate, resulting in the "positive" lymph node. The findings are in keeping with our contention that host factors responsible for metastases, and perhaps metastases themselves, are at least in part responsible for growth of tumor in RLNs. They also have relevance to the site of administration of specific immunotherapeutic agents and to the significance of the removal of RLNs with a primary tumor.

The pathology of invasive breast cancer. A syllabus derived from findings of the National Surgical Adjuvant Breast Project (protocol no. 4)

The inter-relationships of 32 pathologic and 7 clinical parameters encountered in the study of 1000 examples of invasive breast carcinoma have been presented. In some instances the biological significance of these associations is at present unclear. In others it is to be noted that there is no information provided as to the rank of their significance. Nevertheless, the associations that were encountered not only help further characterize the various forms of breast cancer but also provide information regarding the possible biological significance of some of their features. Although it is not our intention to minimize the possible significance of the inter-relationships of pathologic parameters, most emphasis in the summarizing statements which follow has been placed upon those correlations which may relate to prognosis. In this regard reference has been made to short-term treatment failure, vis a vis local recurrence and/or metastases, which may not necessarily accurately reflect patient survival, although generally such a relationship exists. Information in this regard as well as to the rank of the significance of these pathologic features shall be forthcoming when sufficient time has elapsed since the inception of this study to allow for such conclusions, i.e. survival or long-term treatment failure rates. Lastly, it becomes evident that the guidelines followed in the examination of these specimens appear to represent at least the minimum requirements necessary for a meaningful pathologic evaluation of breast carcinoma.

Role of the regional lymph node in neoplasia: cellular mediated reactivity in vitro by autologous regional or distant lymph nodes or peripheral blood lymphocytes of dogs with spontaneous neoplasms

This report concerns the in vitro reactivity of lymphocytes obtained from regional (draining) lymph nodes, distant nodes and peripheral blood against autochthonous spontaneous neoplasms. Tumors, blood and lymph nodes were collected aseptically prior to necropsy. Primary tumor cultures were established. Viable tumor cells were first incubated with media or autologous sera and then various numbers of lymphocytes were added. The mixtures were rotated for 60 minutes and then plated. Two and/or five days later cultures were terminated and viable target cells counted. The results of the tests were similar regardless of the lymphocyte source utilized. In vitro tumor cell cytotoxicity by high numbers (1000:1 lymphocytes to tumor cells) of any autologous lymphocytes and interference of such reactivity by autologous sera were demonstrated. Low numbers (100:1) of any lymphocyte source lead to tumor growth stimulation. Animals with spontaneous neoplasms are probably the best model for the study of human clinical oncology. Our data demonstrate that in these animals lymphocytes obtained from regional nodes were not unique in their reactivity to tumors. It is possible that early in the disease the draining node may play a vital role in initiation of host response; however, later its importance probably diminishes.