Biomedical subjects
Publications and source records attributed to A J Cochran.
The Association of Directors of Anatomic and Surgical Pathology has developed recommendations for the surgical pathology report for common malignant tumors. The recommendations for cutaneous melanoma are reported.
Most studies of the reverse transcriptase in situ polymerase chain reaction technique have reported results from assessments of cultured cells, frozen sections, and cytospin preparations. For application to routine diagnosis, it will be necessary to adapt the technique for use with formalin-fixed, paraffin-embedded tissues, the materials that are generally available. We have evaluated the feasibility of such an approach, using surgical pathology archival material from 25 UCLA patients: 15 tissues from primary and metastatic melanoma, 7 from nonmelanocytic tumors, including cancer of the lung, colon, kidney and skin and a thyroid adenoma, and 3 nontumorous tissues. Seven of 15 melanoma tissues gave a strong positive signal, 5 gave a weak signal, and 3 were negative. None of the 10 nonmelanoma tissues gave a positive signal. The specific reaction product was mainly located in the cytoplasm. None of the nonmelanocytic tumors or normal tissues demonstrated this pattern of cytoplasmic staining. Some nonspecific nuclear staining was observed in melanocytic and nonmelanocytic tumors and must not be overread as a true positive result. It is possible to detect tyrosinase mRNA in formalin-fixed, paraffin-embedded tissue sections of melanoma, but the technique remains too demanding for routine application.
The Association of Directors of Anatomic and Surgical Pathology have developed recommendations for the surgical pathology report for common malignant tumors. The recommendations for cutaneous melanoma are reported herein.
The current classification of cutaneous melanoma was developed in 1972 and revised in 1982. Since that time new concepts and terminology have evolved that require consideration of a further revision. This paper reviews some of the concepts that will form part of that process. Regional meetings of interested parties have been held to review the classification and there will be an open meeting on the topic at the 1997, 4th World Conference on Melanoma in Sydney, Australia. A questionnaire is included that will allow the interested reader to provide comments on the topic.
To evaluate the specificity and applicability to the study of human tumor cells of the reverse transcription (RT) in situ PCR and RT polymerase chain reaction (PCR) in situ hybridization techniques, we examined five melanoma cell lines and five nonmelanoma lines for tyrosinase mRNA using primers specific for tyrosinase. Each procedural step was optimized and minutely controlled, and results from the in situ techniques and solution-phase RT-PCR were compared. All melanoma lines showed a specific pattern of perinuclear cytoplasmic reaction not seen in nonmelanoma lines. There was exact agreement between the results from the RT in situ PCR and RT-PCR in situ hybridization techniques and those from solution-phase RT-PCR. Ribonuclease digestion abolished cytoplasmic staining, as did omission of the reverse transcriptase step. Nuclear staining was seen in melanoma and nonmelanoma lines, apparently as a result of DNA synthesis from repair-replication and mispriming or nonspecific amplification. Neither high concentrations of deoxyribonuclease nor long incubation periods abolished this effect completely. Demonstration of cytoplasmic mRNA by RT in situ PCR and RT-PCR in situ hybridization specifically identifies cells of melanocytic lineage.
Most patients with primary melanoma are cured by local surgery, but a significant minority develop fatal metastases. The ability to identify patients with progressive disease is central to efficient management: permitting optimal deployment of adjunctive therapy and sparing the non-progressing majority the morbidity of aggressive therapy. Accurate prediction on an individual patient basis is the ideal, but the best current prognosticators permit only assignment to risk categories. Formulaic combinations of well tried correlates of outcome (gender, ulceration, depth, thickness, and mitotic rate increase accuracy of prediction, but not to personalised level. The use of large data bases against which the attributes of individual patients may be compared is useful and amalgamation of data bases will increase the availability of this approach. The development of markers of proliferation fraction (PCNA and MIB-1) and of the metastatic phenotype (PNA-receptor status) will further refine the process. Staging of disease is critical. Accuracy of staging is improved by mapping the (sentinel) lymph nodes likely to contain early tumor by lymphoscintigraphy and dye/radiomarker localisation. The application of exquisitely sensitive immunohistochemical and molecular biological techniques to biopsies from tissues likely to be the site of metastases permit assessment of clinical stage with a previously impossible degree of accuracy (ultrastaging).
Eighty-six lymph nodes at measured distances from a primary tumor were removed from 68 patients with malignant melanoma. The ability of lymph-node lymphocytes (LNL) from these nodes to modulate proliferation of a melanoma cell line (UCLA-SO-M14) in vitro was tested. LNL from the majority of lymph nodes (66%) inhibited M14 growth, but LNL from 34% of nodes stimulated growth of the cell line. Peripheral blood mononuclear cells always inhibited M14 growth. Distance of a node from the primary tumor was found to be an important determinant of LNL activity. This was demonstrated using pairs of nodes from individual patients. In 86% of cases, LNL from nodes located nearer to the tumor inhibited M14 growth less than LNL from more distant nodes. Stimulation of M14 growth was commonest with LNL from nodes located near to the tumor. CD8+ T cells were largely responsible for M14 growth inhibition, whereas CD4+ cells were associated with stimulation of M14 growth. Removal of CD4+ lymphocytes from growth stimulatory LNL resulted in a CD4-depleted LNL preparation that inhibited M14 cell proliferation. The environment in lymph nodes located dose to tumors may thus favor growth of metastatic tumor cells.
Tumour cells in malignant melanomas express molecules associated with tumour progression; however, up until now, no marker has been able to identify the tumour cells from which metastases are derived. It has recently been shown that in human melanoma cell lines, populations expressing peanut agglutinin (PNA)-binding glycoproteins are able to generate metastases, and that such cells do exist in primary human melanomas, their presence being associated with the degree of local invasion that governs the metastasis risk. To further investigate the correlation between the expression of PNA-binding glycoconjugates by cells from primary melanomas and the patient's individual risk of recurrence or metastasis, a molecular epidemiological approach employing histochemical techniques within a case-control design was developed. The main objective of this study is to determine whether an histochemical staining with the lectin PNA of cells in the primary lesion is associated with an increased risk of local recurrence of metastasis, and with survival, independently of Breslow's tumour thickness. The study comprises the comparison of the PNA labelling index and of the type and intratumour location of the staining as a function of clinical outcome in two matched series of patients with known clinical outcome: patients who had died at 5 years and patients alive at 5 years (to assess association with survival), and patients who experienced a recurrence within the first 5 years and patients alive without recurrence at 5 years (to assess association with risk of recurrence). A matched case-control design was used with a variable number of controls matched to each case. Apart from age (+/-5 years), sex and centre where diagnosis was made, matching was made on histogenetic type and primary tumour thickness (four categories being considered: <0.75, 0.76-1.5, 1.51-3 and >3 mm).
Nevocytes in melanoma-draining lymph nodes can be mistaken for melanoma metastases and may possibly transform to melanoma. During the development of a new technique for managing high-risk primary melanomas, selective lymph node dissection, we examined 4,821 nodes from 208 melanoma patients by light microscopy and immunohistochemistry. Nodal nevi were identified in 49 of 226 lymphadenectomy specimens (22%), a frequency considerably higher than previously recorded (5-6%). Nevi occurred in 57 of 4,821 nodes (1.2%), in 84% of patients in one node, in 13% of patients in two nodes, and in 3% of patients in three nodes. Nevocytes were detected in hematoxylin and eosin-stained sections in 38 of 49 cases (78%) and exclusively by immunocytochemistry with an antibody to S-100 protein in 11 of 49 (22%). Nevi were in the peripheral capsule in 93% of cases and in internal trabecula in the remaining 7%. Nevocytes surrounded a small vessel in 33% of cases. Nevi were more frequent in axillary (37 of 140, 26%) and cervical nodes (seven of 40, 18%) than in inguinal nodes (five of 46, 11%). Nevi were more frequent in sentinel nodes, the first nodes on the lymphatics draining a primary melanoma (11 of 284, 3.9%), than in nonsentinel nodes (46 of 4,537, 1.01%; p < 0.0008). One of 1,071 nodes from 50 patients with breast cancer (0.1%) and none of 521 nodes from 50 patients with pelvic cancer contained nevocytes. That nodal nevi are selectively present in melanoma patients raises the possibility of their origin from nodal melanocytes influenced by tumor products. Alternatively, the association may indicate that the nevocytes of cutaneous nevi can be disrupted and displaced by the growth of an adjacent melanoma.
Tumor vascularity has been proposed as a prognostic indicator for a number of solid tumors. Although a correlation between microvessel number and metastatic behavior has also been suggested for cutaneous melanoma, the small number of cases studied to date allows one to draw only preliminary conclusions. In this study, we have assessed tumor vascularity in cutaneous melanoma by comparing 60 cases of metastasizing and non-metastasizing tumors matched for tumor thickness, age, sex, and anatomic site. Ulex europaeus agglutinin I appeared to be the most suitable vascular marker for this study. Our results indicate that there was no statistically significant difference between the two groups with regard to tumor vascularity. Even after identifying 15 cases of thin ( < 1.0 mm thick) melanoma, there was no significant difference in the number of microvessels between metastasizing and non-metastasizing tumors. Comparison of patterns of vascular microarchitecture also failed to discriminate between the two groups. Thus, our results indicate that tumor vascularity may not be an independent prognostic factor for cutaneous melanoma.
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BACKGROUND: A fundamental research goal in clinical melanoma studies is to understand the natural history of melanoma and its relationship with prognostic factors. The current understanding of melanoma progression and the relationship of risk factors is based on two-stage modeling. METHODS: The authors propose a multistage Markov model for melanoma progression. This model is applied to a data set consisting of approximately 3900 follow-up staging visits of patients with melanoma. The approach takes into account the heavy censoring encountered in this data set and all chronic, subclinically progressive disease. The Markov transition parameters are expressed as Cox regression functions of the relevant prognostic variables. Parameter estimation is achieved by using a missing-data approach. RESULTS: Tumor thickness, level, and site and patient gender and age at diagnosis are independent risk factors in the transition from local to nodal disease. Tumor thickness and level of invasion and patient age are factors in the transition from local disease to dissemination (without intervening involvement of the nodes). Tumor thickness, patient age, primary site, and the number of involved lymph nodes are factors in the transition from nodal disease to dissemination. Transition from dissemination to death is affected by primary thickness, patient gender, number of nodes involved, and site of metastases. CONCLUSION: This multistage analysis contributes to a more accurate understanding of the progress of melanoma and is likely to be applicable to the study of other progressive diseases. Graphic goodness-of-fit results suggest satisfactory predictability of the model to other data sets.
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Alterations of cell-surface glycoconjugates have been associated with invasiveness and metastatic capacity in a number of experimental and human tumors (bladder and colon cancer). We have recently shown that human melanoma cells from variants selected for high metastatic potential in an animal model bind the lectin peanut agglutinin (PNA), and that human melanoma cell populations enriched for PNA binding cells generated a higher frequency of metastases when xenografted into immune suppressed neonatal rats. We have therefore sought cells binding PNA in biopsied human melanocytic tumors and compared frequencies of PNA binding by cells from benign nevi, early and late primary melanomas, and metastatic melanomas. Sections of conventionally processed tissues were deparaffinised and exposed to biotinylated PNA; PNA fixation was revealed by the avidine/peroxidase/AEC technique. In 51 specimens tested, PNA appears to react electively with invasive tumors, since only one of the 7 early primary melanomas (Clark I-II) reacted while 13/23 late primary melanomas (Clark III-V), and 4/21 melanoma metastases were reactive. In addition, only 1/17 benign nevi bound PNA. In primary tumors, the reactive cells were exclusively invasive tumors cells in the dermis. PNA reactive material was observed in the cytoplasm and plasma membrane of reactive cells. Hence, alterations in composition and cellular localisation of glycoconjugates detectable by lectin histochemistry in melanoma cells may be markers of metastatic potential that may be applicable on an individual patient basis.
The poor survival rate for patients with regional lymph node metastases of malignant melanoma reflects the strong association between lymph node and subsequent visceral metastases. The authors discuss clinical considerations, pathologic risk factors, selective lymphadenectomy, examination of lymph node dissections, difficulties of diagnosis, and prognosis.
BACKGROUND: In previous studies, the authors demonstrated the value of the monoclonal antibody (MoAb) BL2-10D1 in identifying malignant transitional cells. In this study, the authors evaluate the possible diagnostic value of a murine MoAb, BL2-10D1, raised against human bladder cancer in the determination of the urothelial origin of metastases in a series of 29 patients with metastatic bladder or prostatic carcinoma. METHODS: Using an immunoperoxidase method, BL2-10D1 and anti-prostate-specific antigen (anti-PSA) reactivity were studied, using histologic sections from 18 pelvic lymph nodes and 4 other anatomic sites invaded by transitional cell cancer, and from 7 pelvic lymph nodes containing prostatic cancer. RESULTS: All lymph nodes containing metastases of transitional cell carcinoma were positive with BL2-10D1, whereas all metastases of prostatic cancer were negative; the four instances of distant urothelial metastases were positive with BL2-10D1 MoAb. Conversely, anti-PSA reacted only with prostatic metastases. CONCLUSION: Thus, MoAb BL2-10D1 and anti-PSA complement each other in the separation of cancers of prostatic and urothelial origin, and the BL2-10D1 MoAb has potential usefulness in differentiating between urothelial carcinoma and prostate adenocarcinoma. In patients with bladder tumors of uncertain origin, BL2-10D1 may be helpful in confirming that a tumor is a transitional cell carcinoma.
BACKGROUND: The American Joint Committee on Cancer (AJCC) uses both Breslow thickness and Clark level in its staging system for malignant melanoma. Stage I corresponds to Breslow thicknesses less than 1.5 mm and Clark levels II and III. Stage II corresponds to Breslow thicknesses of at least 1.5 mm and Clark levels IV and V. However, most investigators have found Clark level to be of no prognostic significance once Breslow thickness has been taken into consideration by multivariate analysis. METHODS: The authors examined the prognostic significance of Clark level by studying patients in the large database of the John Wayne Cancer Institute. Among 5575 patients with melanoma seen during the past 20 years, complete data on microstaging by both Clark and Breslow methods were available for 3323 patients. The 5-year survival rates were as follows: Clark II, 95%; III, 81%; IV, 68%; V, 47%. The Breslow thicknesses were as follows: < 0.75 mm, 95%; 0.75-1.49 mm, 85%; 1.5-3.99 mm, 66%; > or = 4.0 mm, 46%. RESULTS: By univariate analysis, both Clark level and Breslow thickness were highly significant prognostic indicators (P < 0.0001). By multivariate analysis, Breslow thickness remained significant (P < 0.0001). However, even when Breslow thickness was included in the model, Clark level also remained highly significant (P < 0.0015). CONCLUSIONS: Decisions regarding therapy for patients with clinical Stage I melanoma should consider both Clark level and Breslow thickness of the primary lesion. When there is a discordance between the two methods of microstaging, the AJCC stage should be amended to reflect the least favorable of the two prognostic indicators.
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