Monitoring antitumour immune response during immunotherapy of cancer: why and how?

Cancer remains one of the most important public health concerns facing us today. Despite recent therapeutic developments, conventional therapies have provided only limited success in the management of patients with advanced disease. The recent discovery of tumour-associated antigens has led to a strong interest in immunotherapy as an alternative or adjuvant cancer treatment modality. Despite the expanding volumes of literature on this form of therapy confirming its strong anti-neoplastic effects in animals, much still remains to be elucidated with respect to its clinical applicability and effectiveness in human subjects. Clinical trials evaluating a wide variety of immunotherapeutic approaches in cancer patients are currently underway throughout the world and many have yielded promising preliminary results. In order to reach a better understanding of this potentially powerful therapeutic tool in a timely fashion, a methodical, multi-institutional approach is indispensable. All patients undergoing treatment should be monitored closely in order to correlate specific therapy-induced anti-tumour responses with clinical outcomes. This article provides a brief overview of specific assays currently used to monitor immune responses in these patients. Special emphasis is placed on the theory behind these tests and specific examples from the literature are provided.

Complete response to neoadjuvant chemoradiation for rectal cancer does not influence survival

BACKGROUND

Up to 30% of patients with locally advanced rectal cancer have a complete clinical or pathologic response to neoadjuvant chemoradiation. This study analyzes complete clinical and pathologic responders among a large group of rectal cancer patients treated with neoadjuvant chemoradiation.

METHODS

From 1987 to 2000, 141 consecutive patients with biopsy-proven, locally advanced rectal cancer were treated with preoperative 5-fluorouracil-based chemotherapy and radiation. Clinical restaging after treatment consisted of proctoscopic examination and often computed tomography scan. One hundred forty patients then underwent operative resection, with results tracked in a database. Standard statistical methods were used to examine the outcomes of those patients with complete clinical or pathologic responses.

RESULTS

No demographic differences were detected between either clinical complete and clinical partial responders or pathologic complete and pathologic partial responders. The positive predictive value of clinical restaging was 60%, and accuracy was 82%. By use of the Kaplan-Meier life table analysis, clinical complete responders had no advantage in local recurrence, disease-free survival, or overall survival rates when compared with clinical partial responders. Pathologic complete responders also had no recurrence or survival advantage when compared with pathologic partial responders. Of the 34 pathologic T0 tumors, 4 (13%) had lymph node metastases.

CONCLUSIONS

Clinical assessment of complete response to neoadjuvant chemoradiation is unreliable. Micrometastatic disease persists in a proportion of patients despite pathologic complete response. Observation or local excision for patients thought to be complete responders should be undertaken with caution.

Validation of delayed sentinel lymph node mapping for melanoma

PURPOSE

Sentinel lymph node mapping using radiolabeled tracer and blue dye is widely accepted and applied for staging melanoma. Common practice involves injection of radiolabeled tracer on the morning of surgery. However, optimal timing of radiolabeled colloid injection with respect to surgery remains debated. Injection on the day before surgery would offer the advantages of increased scheduling flexibility and decreased radiation exposure to the patient and operating room staff. We hypothesized that a single injection of radiolabeled colloid given 24 hours before surgery would be sufficient and would possibly improve intraoperative sentinel lymph node identification.

PATIENTS AND METHODS

Ninety-five patients with newly diagnosed cutaneous melanoma underwent injection of radiolabeled colloid and lymphoscintigraphy 18 to 24 hours before surgery for sentinel lymph node mapping and biopsy. Sixty-three patients underwent repeat imaging immediately before surgery, and the images were compared with those obtained the previous day. Intraoperative mapping utilized a hand-held gamma probe and injection of blue dye to identify sentinel lymph nodes.

RESULTS

Two hundred fifty-one sentinel lymph nodes were identified by initial lymphoscintigraphy in 95 patients. Delayed imagingwithout reinjection of radiolabeled tracer compared with the initial lymphoscintigraphy demonstrated no change (71%), clarification of initial ambiguous patterns (10%), or newly identified nodes (19%). Two hundred sixty-one sentinel lymph nodes were resected, of which 79% stained blue. Microscopic metastases were present in 20 sentinel lymph nodes (8%) in 19 patients (20%). All positive nodes contained radioactivity and blue dye.

CONCLUSIONS

A single injection of radiocolloid 24 hours before surgery combined with intraoperative blue dye injection identified all sentinel lymph nodes and did not miss any metastatic disease. In addition, delayed imaging may clarify initial ambiguous findings and identify additional nodes at risk for metastasis. This technique produces sentinel lymph node identification rates, harvest rates, and rates of positivity comparable to those reported with the use of injection of radiolabeled tracer on the day of surgery and greatly facilitates the technical and administrative aspects of sentinel lymph node mapping.

Primary chondroid melanoma

BACKGROUND

Malignant melanoma is notorious for the wide range of histologic patterns it can assume, among the least frequent of which is chondroid melamona.

METHODS

Two cases of primary chondroid melanoma of the distal lower extremity were studied. Tissue for light microscopy was fixed in formalin, embedded in paraffin, and processed routinely. In one case, transmission electron microscopy and immunohistochemical evaluation were performed.

RESULTS

Both cases exhibited melanoma in-situ, a conventional (non-chondroid) invasive component, and areas of chondroid differentiation, as confirmed by strongly positive staining with Alcian blue at pH 2.5 and Safranin O. Immunohistochemically, one case expressed S-100 protein and vimentin, and did not express gp100 (HMB-45), tyrosinase, MART-1, the Mel-5 antigen, the NKI/C3 antigen, CD45Ro, cytokeratin, or desmin. Electron microscopy of the chondroid component revealed occasional tumor cells with rare, membrane-bound, electron-dense organelles; the extracellular compartment showed amorphous ground substance consistent with cartilaginous differentiation.

CONCLUSIONS

Chondroid change in the absence of osteogenic differentiation is extremely rare in malignant melanoma. Melanoma should be considered in the differential diagnosis of primary cutaneous neoplasms exhibiting cartilaginous differentiation.

Neoadjuvant chemoradiation for rectal cancer: analysis of clinical outcomes from a 13-year institutional experience

OBJECTIVE

To examine clinical outcomes in patients receiving neoadjuvant chemoradiation for locally advanced rectal adenocarcinoma.

SUMMARY BACKGROUND DATA

Preoperative radiation therapy, either alone or in combination with 5-fluorouracil-based chemotherapy, has proven both safe and effective in the treatment of rectal cancer. However, data are lacking regarding which subgroups of patients benefit from the therapy in terms of decreased local recurrence and increased survival rates.

METHODS

A retrospective chart review was performed on 141 consecutive patients who received neoadjuvant chemoradiation (5-fluorouracil +/- cisplatin and 4,500-5,040 cGy) for biopsy-proven locally advanced adenocarcinoma of the rectum. Surgery was performed 4 to 8 weeks after completion of chemoradiation. Standard statistical methods were used to analyze recurrence and survival.

RESULTS

Median follow-up was 27 months, and mean age was 59 years (range 28-81). Mean tumor distance from the anal verge was 6 cm (range 1-15). Of those staged before surgery with endorectal ultrasound or magnetic resonance imaging, 57% of stage II patients and 82% of stage III patients were downstaged. The chemotherapeutic regimens were well tolerated, and resections were performed on 140 patients. The percentage of sphincter-sparing procedures increased from 20% before 1996 to 76% after 1996. On pathologic analysis, 24% of specimens were T0. However, postoperative pathologic T stage had no effect on either recurrence or survival. Positive lymph node status predicted increased local recurrence and decreased survival.

CONCLUSIONS

Neoadjuvant chemoradiation is safe, effective, and well tolerated. Postoperative lymph node status is the only independent predictor of recurrence and survival.

Generation of melanoma-specific, cytotoxic CD4(+) T helper 2 cells: requirement of both HLA-DR15 and Fas antigens on melanomas for their lysis by Th2 cells

Recognition of melanoma antigens by HLA class-II-restricted CD4(+) T lymphocytes has been investigated. Two cytotoxic CD4(+) T cell lines were established by stimulating PBLs from a melanoma patient with either parental or IFN-gamma-transduced autologous tumor cells. These T cells secreted IL-4, but not IL-2, IFN-gamma, or TNF-beta, in response to the autologous melanoma cells, suggesting that they belong to the Th2 subtype. Their cytotoxicity was directed against the IFN-gamma-transduced melanoma cells and was HLA-DR-restricted. The autologous and two allogeneic IFN-gamma-modified melanoma cell lines shared melanoma antigen(s) presented in the context of HLA-DR15. HLA-DR15(+) nonmelanoma cells were resistant targets indicating that the shared antigen(s) is melanoma associated. Parental autologous and HLA-DR-matched allogeneic melanoma cell lines, displaying low levels of HLA-DR antigens, induced Th2 proliferation and cytokine release, but were insensitive to lysis prior to upregulation of HLA-DR and Fas antigens by IFN-gamma. Cytolysis was inhibited by anti-HLA-DR and by anti-Fas antibodies, suggesting that the cytolysis is mediated via the Fas pathway. While small amounts of HLA-DR15 molecules on melanoma cells are sufficient for Th2 proliferation and cytokine release, higher amounts of HLA-DR15 and the expression of Fas are required for CD4(+)-mediated lysis.

Identification of higher risk thin melanomas should be based on Breslow depth not Clark level IV

BACKGROUND

There is good prognostic correlation for the two microstaging systems, Breslow depth and Clark level, commonly used to stage melanomas. Many investigators have reported that Breslow depth is the superior microstaging method. Although Clark level has been dropped from most of the proposed American Joint Committee on Cancer (AJCC) melanoma staging system, the AJCC system still includes Clark Level IV as a criterion for upstaging thin melanomas. The authors sought to determine whether this is appropriate, based on melanoma patient data in the Duke Comprehensive Cancer Center database.

METHODS

Of the 8833 patients registered between January 1, 1970 and December 31, 1995, complete data on Breslow depth and Clark level was available for 4560 patients who were without nodal or metastatic disease at presentation. Ten-year survival was measured from the date of excision of the primary tumor until death from melanoma and analyzed using Kaplan-Meier and Cox proportional hazard methodologies.

RESULTS

When analyzed separately, both increased Breslow thickness and Clark level correlated with shorter survival times. During subgroup analysis, Breslow thickness remained a significant prognostic indicator of survival at Clark Levels III and IV. Conversely, at narrow levels of Breslow thickness (i.e., 0-0.75 mm, > 0.75 -1.0 mm, > 1.0-1.5 mm) survival times were indistinguishable between Clark Levels III and IV. For the broader Breslow thickness interval of 0-1.0 mm, a barely significant difference between Clark Levels III and IV could be obtained. However, for this thickness range, even greater differences in survival could be obtained by merely comparing Breslow subgroups (i.e., < or = 0.8 mm vs. > 0.8-1.0 mm, < or = 0.9 mm vs. > 0.9-1.0 mm).

CONCLUSION

The authors' data suggested that, after controlling for Breslow depth, Clark level was not a good prognostic indicator for survival. If the AJCC's objective is to design a classification system that will reliably predict the higher risk melanomas, then the system should be based on tumor thickness, which is clearly a better prognostic indicator, and should not be modified because of Clark level.

Using a continuous transformation of the Breslow thickness for prognosis in cutaneous melanoma

Although the Breslow thickness provides the most important histologic information for prognosis in cutaneous melanoma, controversies and uncertainty remain about how best to use thickness. It is unclear whether cut points should be used, or, if they are used, which are optimal. We studied new data collected from more than 1,000 patients followed up for a relatively long period. From Cox proportional hazards models of survival we learned that more cut points provide more prognostic information than using, for example, just 1 cut point at 1.7 mm. Nevertheless, a continuous transformation provides an effective alternative that captures the information that thickness provides, and it avoids the pitfalls of using multiple cut points. In a multivariate model, this transformation provided strong prognostic information, and the result produced a prognostic score for cutaneous melanoma. This score provides a practical way that Cox model results can be used, and we believe it consolidates the prognostic information provided by traditional histologic and clinical variables. When newer prognostic variables are introduced, we suggest that they be used with this continuous transformation of thickness rather than with cut points in thickness.

A model for pretest probability of lymph node metastasis from cutaneous Melanoma

Although many statistical models have been developed to predict survival in cutaneous melanoma, few predict the end point of regional lymph node metastasis shortly after the diagnosis of melanoma. We used routine clinical and histologic data from 573 patients referred to the Duke University Melanoma Clinic, Durham, NC, during the 1980s and 1990s who underwent lymph node resections during the first year after the diagnosis of primary cutaneous melanoma. The outcome we modeled (using the logistic regression model) was the probability of lymph node metastasis. We found that tumor thickness was the variable most significantly associated with the probability of nodal metastasis, and the presence of ulceration and tumor location also were significant, but age, sex, and mitotic rate were not. When the resulting logistic model predicted that the probability of nodal metastasis was more than .6, 93 of 115 patients had nodal metastasis. When the model predicted that the probability was less than .3, just 32 of 88 patients had positive nodes. Furthermore, after the result of the node sampling was known, Cox model analysis demonstrated that the pretest probability added significant information about subsequent survival.

Gastrointestinal carcinoids: characterization by site of origin and hormone production

OBJECTIVE

To describe a large series of patients with carcinoid tumors in terms of presenting symptoms, hormonal data, stage at diagnosis, pathologic features, and survival.

SUMMARY BACKGROUND DATA

Published series have described significant prognostic features of carcinoid tumors as site of origin, age, sex, stage at diagnosis, presence of high hormone levels, and increased T stage. Of these, stage at diagnosis and T stage seem to emerge most often as independent predictors of survival in multivariate analyses. Of carcinoid tumors, those arising from a midgut location have higher levels of serotonin and serotonin breakdown products, as well as more frequent metastatic disease at presentation, than those arising from either foregut or hindgut locations.

METHODS

A prospective database of carcinoid patients seen at Duke University Medical Center was kept from 1970 to the present. Retrospective medical record review was performed on this database to record presenting symptoms, hormonal data, pathologic features, and survival. Statistical methods included analysis of variance, Kaplan-Meier analysis, and Mantel-Cox proportional hazard survival analysis, with P <.05 considered significant for all tests.

RESULTS

Carcinoids arising in different locations had different presentations: rectal carcinoids presented significantly more often with gastrointestinal bleeding, and midgut carcinoids presented significantly more often with flushing, diarrhea, and the carcinoid syndrome. Patients with midgut tumors had significantly higher levels of serotonin and serotonin breakdown products, corresponding to higher metastatic tumor burdens. Although age, stage, region of origin, and urinary level of 5-hydroxyindoleacetic acid predicted survival by univariate analysis, only the latter three were independent predictors of survival by multivariate analysis. Of the patients with metastatic disease at diagnosis, those with midgut tumors had better survival than those with foregut or hindgut tumors.

CONCLUSIONS

Although region of origin is certainly an important factor in determination of prognosis, stage of disease at presentation is more predictive of survival. Pancreatic and midgut carcinoids are metastatic at diagnosis more often than those arising in other locations, leading to a worse overall prognosis. Among patients with distant metastases, patients with midgut primary tumors have improved survival despite increased hormone production compared with patients with tumors arising in other primary sites.

Positron emission tomography scanning in malignant melanoma

BACKGROUND

Several recent studies have demonstrated the low yield of anatomically based computed tomography scans in evaluating Stage III (American Joint Committee on Cancer) patients with malignant melanoma. The purpose of this study was to investigate the efficacy and clinical utility of functionally based positron emission tomography (PET) scans in the same patient population.

METHODS

A prospective evaluation of 106 whole body PET scans obtained after injection of 2-fluorine-18, 2-fluoro-2-deoxy-D-glucose (FDG) was performed in 95 patients with clinically evident Stage III lymph node and/or in-transit melanoma. Areas of abnormality on FDG PET scanning were identified visually as foci of increased metabolic activity compared with background, and all positive foci were assessed pathologically.

RESULTS

In this patient population, there were 234 areas that were evaluated pathologically of which 165 were confirmed histologically to be melanoma. PET scanning identified 144 of the 165 areas of melanoma for a sensitivity of 87.3%. The 21 areas of melanoma that were missed included 10 microscopic foci, 9 foci less than 1 cm, and 2 foci greater than 1 cm. There were 39 areas of increased PET activity that were not associated with malignancy for a 78.6% predictive value of a positive test. Of the 39 false-positive areas (false-positive rate of 56.5%), 13 could be attributed to recent surgery, 3 to arthritis, 3 to infection, 2 to superficial phlebitis, 1 to a benign skin nevus, and 1 to a colonic polyp. Pathologic evaluation of the remaining false-positive areas failed to reveal a definitive etiology for their increased activity on PET scan. With the application of pertinent clinical information, the predictive value of a positive PET scan could be improved to 90. 6%. The specificity of PET scanning in this study was only 43.5% because very few prophylactic lymph node dissections were performed. Thirty-six of the total 183 abnormal areas (19.7%) on PET scanning proved to be unsuspected areas of metastatic disease. These findings led to a change in the planned clinical management in patients after 16 of the 106 PET scans (15.1%).

CONCLUSIONS

FDG PET scanning can be helpful in managing patients with Stage III melanoma in whom further surgery is contemplated. Although false-positive areas are not uncommon, PET scans did change the management of patients 15% of the time. PET's inability to identify microscopic disease suggests that it is of limited use in evaluating patients with Stage I-II disease.

Subungual melanoma. A review of 93 cases with identification of prognostic variables

From 1970 to 1996, 93 patients received diagnoses of subungual melanoma. Followup data were complete on all patients and reviewed with a median duration of followup of 5.2 years. This study identifies significant clinicopathologic variables that affect survival and provides the orthopaedic surgeon assistance in the early diagnosis and treatment of this lesion. Eight-three percent of patients presented with Stage I disease, whereas 17% had nodal or distant disease. Fifty-three percent had locally advanced disease at presentation. Twelve percent of the patients were African-American. Fifty-five percent of the lesions arose on the hands with thumb involvement predominating in more than half of these cases. Operative therapy consisted of amputation. Elective lymph node dissection was performed in 34 patients (37%) for Stage I tumors of intermediate thickness. Therapeutic node dissection was required in 16 patients (17%) for positive nodes. Five-year survival was 74% for patients with Stage I disease and 40% for patients with Stage II disease. Statistical analysis identified stage at diagnosis, Clark and Wihm's level, the patient's race, and the presence of ulceration as prognostic variables affecting survival. The diagnosis of subungual melanoma carries a grave prognosis and often is misdiagnosed in the early stages. The treatment of choice is amputation at the appropriate level.

Dendritic cells infected with a vaccinia vector carrying the human gp100 gene simultaneously present multiple specificities and elicit high-affinity T cells reactive to multiple epitopes and restricted by HLA-A2 and -A3

To investigate the ability of human dendritic cells (DC) to process and present multiple epitopes from the gp100 melanoma tumor-associated Ags (TAA), DC from melanoma patients expressing HLA-A2 and HLA-A3 were pulsed with gp100-derived peptides G9154, G9209, or G9280 or were infected with a vaccinia vector (Vac-Pmel/gp100) containing the gene for gp100 and used to elicit CTL from autologous PBL. CTL were also generated after stimulation of PBL with autologous tumor. CTL induced with autologous tumor stimulation demonstrated HLA-A2-restricted, gp100-specific lysis of autologous and allogeneic tumors and no lysis of HLA-A3-expressing, gp100+ target cells. CTL generated by G9154, G9209, or G9280 peptide-pulsed, DC-lysed, HLA-A2-matched EBV transformed B cells pulsed with the corresponding peptide. CTL generated by Vac-Pmel/gp100-infected DC (DC/Pmel) lysed HLA-A2- or HLA-A3-matched B cell lines pulsed with the HLA-A2-restricted G9154, G9209, or G9280 or with the HLA-A3-restricted G917 peptide derived from gp100. Furthermore, these DC/Pmel-induced CTL demonstrated potent cytotoxicity against allogeneic HLA-A2- or HLA-A3-matched gp100+ melanoma cells and autologous tumor. We conclude that DC-expressing TAA present multiple gp100 epitopes in the context of multiple HLA class I-restricting alleles and elicit CTL that recognize multiple gp100-derived peptides in the context of multiple HLA class I alleles. The data suggest that for tumor immunotherapy, genetically modified DC that express an entire TAA may present the full array of possible CTL epitopes in the context of all possible HLA alleles and may be superior to DC pulsed with limited numbers of defined peptides.

Analysis of prognosis and disease progression after local recurrence of melanoma

BACKGROUND

Local recurrence of melanoma is associated with a grave prognosis. However, the characteristics and the mode of disease progression for patients with local recurrence have not been adequately addressed in the literature.

METHODS

A retrospective analysis of patients treated at a single institution revealed a subset of patients (n = 648) with local recurrence of melanoma as a first event. Patient characteristics, histologic determinants, and disease free interval were variables used to identify prognostic factors.

RESULTS

In this group of patients, male gender (P = 0. 0163), increasing age (P = 0.0001), head and neck primaries (P = 0. 0001), thicker Breslow depths (P = 0.0022), deeper Clark levels (P = 0.0010), and ulceration of the primary tumor (P = 0.0348) suggested a shorter time until local recurrence. Breslow depth (P = 0.0004), Clark level (P = 0.0043), and ulceration (P = 0.0001) still factored into the survival prognosis after recurrence. Truncal primaries (P = 0.0005) and shorter disease free intervals (P = 0.0098) were also associated with poorer outcomes after recurrence. Of the 648 patients, 124 showed no progression, 196 developed another local recurrence, 178 developed in-transit/lymph node metastases, and 150 had systemic recurrences. Survival was only 33.6% for patients with further metastases, compared with 77.4% for patients with no progression of disease after a median follow-up of 38.9 months.

CONCLUSIONS

There was a 48.5% mortality rate at 5 years of follow-up after local recurrence. Long term survival (> 10 years) was estimated to be 34.9%. The patterns of failure after local recurrence suggest that patients may benefit from aggressive locoregional therapy.

Murine dendritic cells transfected with human GP100 elicit both antigen-specific CD8(+) and CD4(+) T-cell responses and are more effective than DNA vaccines at generating anti-tumor immunity

Dendritic cells (DCs) are potent inducers of cytotoxic T lymphocytes (CTLs) when pulsed with an antigenic peptide or tumor lysate. In this report, we have used liposome-mediated gene transfer to examine the ability of plasmid DNA encoding the human melanoma-associated antigen gp100 to elicit CD8(+) and CD4(+) T-cell responses. We also compared the efficacy between gp100 gene-modified DCs and naked DNA (pCDNA3/gp100)-based vaccines at inducing anti-tumor immunity. DCs were generated from murine bone marrow and transfected in vitro with plasmid DNA containing the gp100 gene. These gp100-modified DCs (DC/gps) were used to stimulate syngeneic naive spleen T cells in vitro or to immunize mice in vivo. Antigen-specific, MHC-restricted CTLs were generated when DC/gps were used to prime T cells both in vitro and in vivo. Thus, these CTLs were cytolytic for gp100-transfected syngeneic (H-2(b)) tumor MCA106 (MCA/gp) and vaccinia-pMel17/gp100-infected syngeneic B16 and MCA106, but not parental tumor MCA106 and B16, or gp100-transfected allogeneic tumor P815 (H-2(d)). Immunization with DC/gp protected mice from subsequent challenge with MCA/gp but not parental MCA106. Antibody-mediated T-cell subset depletion experiments demonstrate that induction of CTLs in vivo is dependent on both CD4(+) and CD8(+) T cells. Furthermore, DC/gp immunization elicits an antigen-specific CD4(+) T-cell response, suggesting that DC/gps present MHC class II epitopes to CD4(+) T cells. In addition, our data show that gene-modified, DC-based vaccines are more effective than the naked DNA-based vaccines at eliciting anti-tumor immunity in both prophylactic and therapeutic models. These results suggest that the use of DCs transfected with plasmid DNA containing a gene for TAA may be superior to peptide-pulsed DCs and naked DNA-based vaccines for immunotherapy and could provide an alternative strategy for tumor vaccine design.

Timing of sentinel lymph node mapping after lymphoscintigraphy

BACKGROUND

Sentinel lymph node (SLN) mapping is an effective technique for staging patients with melanoma. In an attempt to avoid reinjection of radiolabeled colloid and facilitate SLN mapping at the time of surgery, we examined whether residual radioactivity from preoperative lymphoscintigraphy could be used to accurately identify SLNs during surgery 18 to 24 hours later.

METHODS

Forty-six patients with newly diagnosed melanoma underwent injection of 0.22-micron filtered technetium 99m-labeled sulfur colloid followed by lymphoscintigraphy. Patients returned the next day for SLN biopsy with Isosulfan blue dye and the hand-held gamma-probe to identify SLNs. Thirty of 46 patients underwent repeat imaging before operation. No patient had reinjection of radiocolloid.

RESULTS

Ninety-five SLNs were identified on initial lymphoscintigraphy, and repeat imaging on the day of surgery confirmed all SLNs previously identified. A total of 122 SLNs (2.65 per patient) were resected from 58 basins. Eighty-four (69%) of 122 SLNs stained blue, and 118 (97%) of 122 SLNs had in vivo gamma-counts greater than 4 times background. Microscopic metastases were present in 13 (10.7%) of 122 SLNs in 12 (26.1%) of 46 patients. There have been no recurrences over a mean follow-up time of 320 days.

CONCLUSIONS

Intraoperative gamma-probe detection combined with blue dye injection is highly effective in identifying SLNs 18 to 24 hours after injection of 0.22-micron filtered 99mTc-sulfur colloid. Reinjection of radiocolloid is not required. This technique avoids radiopharmaceutical administration in the operating room, minimizes radiation exposure, and increases scheduling flexibility.

MCA106 fibrosarcoma cells transduced with granulocyte/macrophage colony-stimulating factor are not superior to the wild-type cells in suppressing the growth of hepatic metastases

BACKGROUND AND OBJECTIVES

Vaccination with cytokine gene-modified tumor cells augments the immune response against established tumors and protects against tumor challenges. In this study, we investigated the vaccine potential of GM-CSF-transduced MCA106 fibrosarcoma (MCA-GMCSF) cells in the C57BL/6 (B6) murine hepatic metastasis model.

METHODS

Experimental mice received one to three weekly vaccines (subcutaneous/intramuscular, s.c./i.m.) of irradiated, parental, or GM-CSF-transduced MCA106 tumor cells. One week after the last immunization, hepatic metastases were established through the intrasplenic injection of live MCA106 parental (MCA106P) tumor cells. The animals were then sacrificed 3-4 weeks after surgery for evaluation of hepatic tumor burden.

RESULTS

Based on in vivo experiments, both GM-CSF-modified and parental MCA106 tumor cell vaccines induced strong protection against hepatic tumor growth with grossly visible tumors rarely identified. This protection was evident even at a single vaccine dose of as low as 1x10(5) irradiated cells. Unimmunized control mice, on the other hand, consistently developed substantial hepatic tumors. Cytotoxicity assays on splenocytes (cultured in vitro for 4-5 days) showed that both groups of vaccinated mice developed strong tumor-specific cytotoxic T-lymphocyte (CTL) responses. Immunohistochemical analysis of injection sites showed infiltration of dendritic cells (DCs) and macrophages into subcutaneously injected MCA-GMCSF cells. Mostly macrophages, however, were seen at the injection site of MCA106P cells. Furthermore, the MCA106P cells expressed high levels of MHC class I antigens and the level of expression was not significantly altered by transduction with the GM-CSF gene. The high expression of MHC class I antigens probably contributed to the strong immunogenicity of the MCA106P cell vaccine.

CONCLUSIONS

This study demonstrates that MCA106 parental cells are as effective as the GM-CSF-transduced cells in suppressing the growth of hepatic metastases. The cellular immune responses induced by these two vaccines, however, are probably mediated by different subsets of host effector cells. These results have important implications for the use of GM-CSF-transduced cell vaccines in the immunotherapy of tumors that have the propensity to metastasize through the lymphatic channels and the circulatory system.

Melanoma of the gallbladder: a review of cases seen at Duke University Medical Center

BACKGROUND

Both primary and metastatic melanoma of the gallbladder are rare. In cases involving isolated tumors of the gallbladder, there continues to be controversy regarding the establishment of primary status. Despite appropriate therapy, the diagnosis of either condition portends a poor prognosis, with few patients surviving more than 2 years.

METHODS

A review of all patients seen at Duke University Medical Center since 1970 generated 1 case of primary and 19 cases of secondary melanoma of the gallbladder. These were analyzed with respect to presentation, clinical and pathologic diagnosis, treatment, and prognosis.

RESULTS

The sole patient with a primary lesion presented with acute cholecystitis. Ultrasound demonstrated a mass in the lumen of the gallbladder. Cholecystectomy revealed melanoma, and the patient eventually died of disseminated disease 13.5 months later. Survival was poor for patients who presented with metastases to the gallbladder in the setting of widespread disease, with 0% survival at 1 year (n=11). Those with isolated, resectable lesions fared better overall, with 100% survival (n=6) at 1 year. One patient remains alive and free of disease 13.8 years later, which, to our knowledge, represents the longest documented survival for a patient with melanoma that has metastasized to the gallbladder.

CONCLUSIONS

Surgery remains the mainstay of therapy for patients with gallbladder melanoma and appears to improve patient outcome in the setting of resectable disease. Hopefully, further investigations will lead to standardized protocols for the treatment of these lesions.

Tumor cells cotransduced with B7.1 and gamma-IFN induce effective rejection of established parental tumor

Genetic modification of tumor cells with the gene for the B7.1 or with the genes for cytokines results in increased tumor cell immunogenicity. In the work reported here, immunization of naive animals with either B7.1 or gamma-IFN gene-modified MCA106 tumor cells effectively protects the host from subsequent challenge with parental tumor. The same treatment fails to induce regression of established tumors, although tumor-specific CTL are generated in the tumor-bearing animals. In contrast, a large tumor burden of the MCA106 fibrosarcoma can be successfully eliminated by treatment with MCA106 tumor cells cotransduced with the B7.1 and gamma-IFN genes. Antitumor immunity induced by the cotransductants is primarily dependent on CD8+ T cells and partly on CD4+ T cells and NK cells, and the enhanced therapeutic effect may be attributed to the in vivo increase of CTL precursors following treatment. The gamma-IFN and B7.1 genes must be expressed on the same tumor cell for optimal therapeutic effect. Our results suggest that tumor vaccines with a potent immunoprotective effect do not necessarily have therapeutic potential and that weakly immunogenic tumors may be rendered highly immunogenic by cotransfection with the genes for B7.1 and gamma-IFN.

Malignant melanoma of the mucous membranes: a review of 119 cases

BACKGROUND

Melanomas arising from the mucous membranes lining the respiratory, digestive, and genitourinary tracts are rare. Women are more commonly affected than are men, mainly because there is no male counterpart for vulvovaginal lesions. The mainstay of therapy is surgery, with little current use of adjuvant modalities in primary therapy. These lesions usually are advanced at initial presentation; consequently, the prognosis is poor, with 5-year survivals well below 50% in most series.

METHODS

One hundred and nineteen patients with primary mucosal melanoma were reviewed. They represented 1.1% of the 10,393 melanoma patients seen at Duke University between 1970 and 1995. All data were obtained from the patients' clinic charts and computerized databases.

RESULTS

There were 43 tumors arising from the head and neck region, 46 from the urogenital tract, and 30 from the anorectum. A female predominance was observed, with a female-to-male ratio of 2.7:1. All but five of the patients underwent resection with curative intent. Regional or distant metastases, or both, were encountered in 36 patients at the time of presentation. In patients with head and neck and urogenital tumors, local recurrences accounted for most of the treatment failures, whereas systemic recurrences were more common with tumors arising in the anorectum. The age and gender of the patient, anatomic site of origin of the tumor, clinical stage at initial presentation, and ulceration of the primary all clearly affected prognosis. Overall, the probabilities of being alive 1, 5, and 10 years after diagnosis were 80%, 29%, and 15%, respectively.

CONCLUSIONS

Widely accepted classification systems are needed so that results from separate institutions can be compared adequately. Multi-institutional trials could help in delineating standardized therapeutic protocols and in establishing the potential roles of emerging modalities in the treatment of this subtype of melanoma.

Reporting fine-needle aspirates of breast: a survey of preferences among surgeons

BACKGROUND

The optimal format for reporting results of breast fine-needle aspiration cytology is controversial, with some experts favoring a five-category system and others recommending a four-category format.

METHODS

A survey of 200 surgeons was performed to determine their preference for a four- or five-category report format. They were also questioned concerning the number of patients per year in whom they diagnosed breast cancer, if they used fine-needle aspiration cytology (FNAC) regularly, and why they favored one category over the other.

RESULTS

Eighty-five complete responses were received. Fifty-eight percent of these surgeons (49) routinely used FNAC for the diagnosis of breast nodules. There was no strong preference for either report format. Twenty-four of 49 routine users of FNAC favored a four-category format, and another four had no preference.

CONCLUSION

Surgeons who routinely used FNAC in the diagnosis of breast disease do not have a preference for the five-category probabilistic system.

Mucosal melanoma of the female genitalia: a clinicopathologic study of forty-three cases at Duke University Medical Center

BACKGROUND

Mucosal melanoma of the female genitalia is a rare neoplasm. Only nine reports reviewing more than 40 patients have been published on this subject in the past 30 years. These lesions arise from melanocytes, which can be found within the mucosa lining the female genital tract. Surgical resection is the mainstay of therapy, with little use for other modalities except in palliative roles. The overall prognosis is poor, with reported 5-year survival rates usually below 50%.

METHODS

Forty-three patients with primary mucosal melanoma of the female genitalia seen at the Duke University Medical Center Melanoma Clinic during a 25-year period were studied retrospectively. Specific information was obtained from the patients' clinic charts and computerized databases.

RESULTS

Thirty vulvar, nine vaginal, and four cervical lesions were identified. The median age at diagnosis was 61.4 years. At initial presentation, two thirds of the patients had localized disease only. Tumor ulceration and thickness of the primary lesion had a measurable impact on prognosis, whereas the presence of regional metastases at presentation did not. All but one patient underwent resection with curative intent. The performance of radical operations did not improve outcome among patients with vulvar melanoma. Many of the treatment failures were the result of local recurrences, hinting at the need to improve local control. Despite therapy, the overall corrected 5-year survival rate was 54%.

CONCLUSIONS

Prospective multicenter trials for patients with vulvovaginal melanoma could be helpful in establishing uniform, standardized surgical protocols and delineating the applicability of new modalities and therapies, such as lymphoscintigraphy with sentinel node biopsy and high-dose interferon.

Human dendritic cells, pulsed with either melanoma tumor cell lysates or the gp100 peptide(280-288), induce pairs of T-cell cultures with similar phenotype and lytic activity

Dendritic cells (DCs) pulsed with unfractionated tumor cell lysates or defined tumor peptides provide potent vaccines which elicit strong antitumor immunity. In this study, we generated DCs from the 2-h adherent progenitor cells obtained from the peripheral blood of melanoma patients. These DCs were able to capture biotinylated melanoma tumor cell lysates. We examined the efficacy of immunogens composed of DCs loaded either with the melanoma peptide gp100 [amino acids 280-288 (DC/gp100)] or with lysates from melanoma tumor cells (DC/lysates) in inducing cytotoxic T-cells from autologous PBLs of HLA-A2 melanoma patients. After four to five weekly stimulations of bulk PBLs with DC/gp100 or DC/lysates, the cultures were enriched with CD3+ T-cells and exhibited one of three phenotypic and functional patterns: (1) Predominant expression of CD8+ and MHC class I-restricted CTLs which displayed strong lytic activity against melanoma cells and T2 cells loaded with the gp100 peptide, (2) mixed CD4+/CD8+ phenotype and weak lytic activity, or (3) nonlytic and predominantly CD4+ cultures. Interestingly, T-cell cultures from each patient exhibited similar phenotypes and lytic activities whether the stimulant was DC/gp100 or DC/cell lysates. Our study demonstrates that DCs pulsed with soluble melanoma peptides or cell lysates are capable of inducing CD8+ CTLs from autologous PBLs of some, but not all, melanoma patients. The function and phenotype of the generated T-cell cultures are governed by DCs since both antigens (the gp100 peptide and melanoma lysates), when presented by a given DC preparation, induced similar T-cell cultures. In summary, it may be difficult to predict the nature of the cellular responses elicited by DC/tumor antigen vaccines from patient to patient.

Vaccination with dendritic cells inhibits the growth of hepatic metastases in B6 mice

Dendritic cells (DC) are specialized antigen-presenting cells that can activate naive and mature T-cells, induce cellular immunity, and stimulate strong antitumor reactions in vivo. This study was undertaken to examine the function of DC vaccines in suppressing the growth of hepatic metastases in C57BL/6 mice. Experimental mice received two i.v. doses of 1 x 10(6) bone marrow-derived DC, either unpulsed or pulsed with MCA-106 fibrosarcoma cell lysates, on days -14 and -7. Controls were injected with HBSS. Hepatic metastases were established on day 0 through intrasplenic injections of 1 x 10(5) MCA-106 tumor cells. Animals were sacrificed on day 21 and their livers were excised to assess tumor burden. Splenocytes from DC-treated groups were cytotoxic against MCA-106 cells, but not against the L929 and CT26 (syngeneic fibroblast and colon tumor, respectively) cell lines. All control mice developed grossly evident hepatic metastases, while 62 and 44% of the mice receiving MCA-106 cell lysate-pulsed DC and unpulsed DC vaccines, respectively, were completely free of tumor. Mean hepatic mass for the controls, including tumor, was almost double that for treated animals. Antibody depletion of either CD4+ or CD8+ lymphocytes abrogated the protective effect of the vaccine. This study demonstrates that immunization with DC confers cellular immunity, with both CD4+ and CD8+ T-cells playing a significant role, and impedes the subsequent establishment and growth of hepatic metastases in mice. The antitumor capabilities of DC justify their use in immunotherapeutic vaccines against human cancers.

Demographics, prognosis, and therapy in 702 patients with brain metastases from malignant melanoma

Brain metastases are a common and devastating complication in patients with malignant melanoma. Therapeutic options for these patients are limited, and the prognosis is usually poor.

OBJECT

A retrospective review of 6953 patients with melanoma treated at a single institution was undertaken to identify demographic factors associated with the development of clinically significant brain metastases in 702 of these patients and to determine the factors influencing the prognosis of this population to permit more informed recommendations regarding surgical therapy.

METHODS

Factors found to be associated with the development of brain metastases included male gender, primary lesions located on mucosal surfaces or on the skin of the trunk or head and neck, thick or ulcerated primary lesions, and histological findings of acral lentiginous or nodular lesions. The overall median survival time of all patients with brain metastases was 113.2 days, and these metastases contributed to the death of 94.5% of the patients in this group. Patients with primary lesions located in the head or neck region had a significantly shorter survival time relative to other patients with brain metastases, whereas patients with a single brain metastasis, patients without lung or multiple other visceral metastases, and patients whose initial presentation with melanoma included a brain metastasis had a significantly better prognosis. The small group of patients who survived for more than 3 years was characterized by the presence of a surgically treated, single brain metastasis in the absence of other visceral metastatic disease.

CONCLUSIONS

Although most patients with brain metastases resulting from melanoma have a dismal prognosis, some who are likely to survive for longer periods can be identified. In these patients surgical resection can significantly prolong meaningful survival. The decision to recommend surgery should be based primarily on the resectability of the brain metastases and on the status and number of other organs with metastatic lesions.

Primary malignant melanoma of the esophagus

A 48-year-old woman presented with a 6-month history of dysphagia, often associated with retrosternal chest pain. Upper endoscopy revealed an unusual pigmented lesion within the middle portion of the esophagus, and multiple biopsies were obtained. The histopathology and immunohistochemical profile of the tissue specimens were diagnostic of malignant melanoma. A thorough clinical and radiographic evaluation was performed, providing no additional findings or alternative primary source. Of approximately 11,500 melanoma patients entered in the Duke University melanoma database since 1970, this represents the only case of primary esophageal melanoma. The case is described and a review of the literature is presented.

Primary malignant melanoma of the esophagus

A 48-year-old woman presented with a 6-month history of dysphagia, often associated with retrosternal chest pain. Upper endoscopy revealed an unusual pigmented lesion within the middle portion of the esophagus, and multiple biopsies were obtained. The histopathology and immunohistochemical profile of the tissue specimens were diagnostic of malignant melanoma. A thorough clinical and radiographic evaluation was performed, providing no additional findings or alternative primary source. Of approximately 11,500 melanoma patients entered in the Duke University melanoma database since 1970, this represents the only case of primary esophageal melanoma. The case is described and a review of the literature is presented.

A Phase I clinical trial of immunotherapy with interferon-gamma gene-modified autologous melanoma cells: monitoring the humoral immune response

BACKGROUND

Tumor cells transduced with cytokine genes provide immunogenic vaccines for cancer immunotherapy.

METHODS

A Phase I clinical trial was conducted for the specific active immunization of melanoma patients with interferon-gamma (IFN-gamma) gene-modified autologous melanoma tumor cells. Short term melanoma cultures were transduced retrovirally with the gene for human IFN-gamma. The genetically modified melanoma cells secreted biologically active IFN-gamma and showed enhanced expression of major histocompatibility complex class I and class II surface antigens. These cells were inactivated by irradiation (50 gray) and were cryopreserved for the vaccine. Twenty melanoma patients were enrolled in this clinical trial. The immunizations were administered in escalating doses once every 2 weeks for 3 months. The first and second injections consisted of 2 million cells, followed by 6 million for the third and fourth injections, and then 18 million for the fifth and sixth injections. The humoral immune responses of the patients were assessed by enzyme-linked immunoadsorbent assay, radioimmunoassay, and radioimmunoprecipitation.

RESULTS

Thirteen of the 20 patients completed the immunization protocol. Eight of these 13 patients showed a humoral immunoglobulin (Ig)G response against autologous and allogeneic melanoma cells. The other five patients either had no detectable antimelanoma antibodies or showed a weak IgG response that did not rise significantly above the preimmune level. All the sera contained low or undetectable levels of antimelanoma IgM antibodies. The IgG response increased progressively in titer during the course of immunization. The positive sera showed preferentially strong binding to melanoma cell lines and some cross-reactivity to nonmelanoma tumors. A 75-80 kD antigen on melanoma cells was immunoprecipitated by postimmune sera of 3 of the responding patients. Preimmune sera from these three patients and sera from other patients immunized with a standard nontransduced melanoma cell vaccine failed to precipitate this antigen. Two patients with significant increases in serum IgG had clinical tumor regression, and two additional patients with low serum IgG response had transient shrinkage of nodular disease during therapy.

CONCLUSIONS

These data suggest that gene therapy with IFN-gamma-transduced melanoma cells is safe and worthy of further investigation in patients with less advanced stage malignant melanoma. The ability to monitor changes in the humoral responses of the immunized patients has been demonstrated.

Immunotherapeutic potential of tumor antigen-pulsed and unpulsed dendritic cells generated from murine bone marrow

Dendritic cells (DC) are highly efficient antigen-presenting cells able to capture, process, and present antigens to naive and primed T-cells. In this study, we have investigated the ability of DC, derived from murine bone marrow and pulsed with tumor cell extracts, to induce regression of preexisting tumors. In an experimental model of B16 melanoma in B6 mice, a significant reduction in metastatic nodules in the lungs was observed in tumor-bearing animals treated with either DC alone or DC pulsed with tumor extracts. Kinetic studies demonstrate that the efficacy of these tumor vaccines is inversely related to tumor burden. In this model, tumor-specific cytotoxic T-cells (CTL) could also be induced in vitro from spleen cells derived from tumor-bearing animals treated with DC pulsed with tumor extracts. Untreated mice had no CTL. Furthermore, DC alone elicited tumor-specific CTL responses in tumor-bearing mice, but not in naive mice. Immune cell depletion experiments show that the therapeutic effects of DC are primarily mediated by CD8+ T-cells, while CD4+ T-cells and NK cells are involved in DC-mediated antitumor immunity to a limited extent. These results illustrate the potential use of DC and DC pulsed with tumor extracts as potent therapeutic reagents for cancer and provide a rationale for using DC in vivo to eliminate disseminated tumors or residual tumor deposits following surgery.

Generation of primary tumor-specific cytotoxic T lymphocytes from autologous and human lymphocyte antigen class I-matched allogeneic peripheral blood lymphocytes by B7 gene-modified melanoma cells

Expression of B7.1 costimulatory molecules on tumor cells has been shown to elicit antitumor immunity in mice. In the present study, we have developed a human B7.1 retroviral vector system to effectively transduce human melanoma cell lines and investigated the potential role of B7.1 in the generation of tumor-specific CTLs from peripheral blood lymphocytes (PBLs) in vitro. We have demonstrated that B7.1-modified melanoma cells are able to induce primary CTL activity from autologous, human lymphocyte antigen (HLA) class I-matched allogeneic PBLs and purified CD8+ T cells in the absence of exogenous cytokines. CTLs generated by B7.1 are tumor specific and HLA class I restricted, and CD8+ T cells are primarily responsible for this specific cytotoxicity. Furthermore, CTLs generated from HLA class I-matched PBLs by B7.1 are cytolytic to tumor cells autologous to the stimulated PBLs. These data suggest that B7.1-modified tumor cells can be used as a potent tumor vaccine for both autologous and HLA class I-matched allogeneic patients.

Eradication of melanoma pulmonary metastases by immunotherapy with tumor cells engineered to secrete interleukin-2 or gamma interferon

This study was undertaken to investigate the effectiveness of interleukin-2 (IL-2) and gamma interferon (gammaIFN)-modified B16 melanoma cells in the immunotherapy of established melanoma pulmonary metastases. The genes for IL-2 and gammaIFN were introduced retrovirally into B16 melanoma cells. Transduction with the gammaIFN, but not the IL-2, gene caused significant increases in the expression of major histocompatibility complex (MHC) antigens on B16-gammaIFN cells. The in vivo tumor-forming capacity of both IL-2- and gammaIFN-transduced B16 cells was drastically reduced when the cells were inoculated subcutaneously (SC) in syngeneic C57BL/6 mice. After intravenous (IV) inoculation, most of the B16-gammaIFN cells were rejected, but B16-IL-2 cells were relatively tumorigenic and formed pulmonary metastases. C57BL/6 mice bearing 4-day established parental B16 lung metastases were treated with B16 parental (B16P) unmodified cells, IL-2- or gammaIFN-modified B16 cells, or a combination of both transduced cells. Treatment consisted of a weekly intraperitoneal (IP) injection of one million irradiated (10,000 rad) tumor cells alone or in combination with exogenous IL-2 for a total of three to four injections. Immunotherapy with B16 parental or B16-IL-2 secreting cells caused a moderate reduction in the number of lung metastases. However, mice treated with gammaIFN-secreting B16 cells showed a significant reduction or complete elimination of lung metastases. There was no additive effect for combining both IL-2- and gammaIFN-modified tumor cells in the immunotherapy. Exogenous IL-2 (50,000-100,000 U/day for 3 days) caused a significant enhancement of the immunotherapeutic benefit of the vaccines. Moreover, mice treated with gammaIFN-modified B16 cells survived longer than the other groups. Twenty-five percent of these mice were tumor free and remained alive for an observation period of 4 months. The in vitro cytolytic activity of splenocytes in chromium release assays did not correlate in every case with the in vivo antitumor effect of the treatment. Our findings have implications for the use of cytokine-modified cells for immunotherapy and for evaluating the therapeutic benefit of this novel treatment.

Modulation of specific active immunization against murine melanoma using recombinant cytokines

Specific active immunization with tumour cells and IL-1beta or IL-2 was examined in a murine model. Mice were treated with irradiated B16 melanoma, IL-1beta or IL-2 only, or with B16 plus cytokines prior to i.v. challenge with viable B16. Lung metastases were recorded after 28 days. Treatment with cytokine alone was not protective. Treatment with B16 alone afforded moderate protection. Treatment with B16 in combination with either cytokine resulted in a significant level of B16 specific protection which was dependent on the dose of cytokine used. Multiple immunizations with B16 provided limited protection which was significantly improved with IL-2. Immunization with B16 in combination with both cytokines at doses that alone failed to enhance immunity resulted in significant protection, suggesting that the two cytokines act at least additively. These studies demonstrate the significant benefit of specific active immunization with tumour cells in combination with low doses of IL-1beta or IL2.

Recognition and lysis of human melanoma by a CD3+, CD4+, CD8- T-cell clone restricted by HLA-A2

The in vitro cytotoxic response to human melanoma is characterized by CD3+ CD8+ T-cells which recognize shared peptide antigens presented in the context of HLA class-I-encoded gene products. We report here studies of a CD3+, CD4+, CD8-, HLA-A2-restricted, melanoma-specific cytotoxic T-cell clone derived by limiting dilution from a T-cell line induced in PBLs from a melanoma patient following in vitro stimulation with an HLA-A2-matched melanoma cell line. The CD4+ cytotoxic T-cell clone is lytic only for melanomas which share the HLA-A2 allele, and the cytotoxicity is blocked by antibody to the T-cell receptor and by antibody to HLA class I. The clone proliferates only following stimulation with HLA-A2-matched melanoma tumor cells. The data suggest that cytotoxic CD4+ T-cells may play a significant role in immunity to melanoma, and HLA class-I-restricted recognition of melanoma may not necessarily require the CD8 molecule on the lytic T-cell.

Effect of irradiation on cytokine production, MHC antigen expression, and vaccine potential of interleukin-2 and interferon-gamma gene-modified melanoma cells

Recent studies have shown that tumor cells transduced with interleukin-2 (IL-2) or interferon-gamma (IFN-gamma) genes stimulated a potent and specific antitumor immunity in experimental animals. For use as a human vaccine, tumor cells must be inactivated by irradiation to ensure the arrest of their growth. This study was undertaken to examine the effects of irradiation (10,000 rad) on the growth characteristics and vaccine potential of IL-2 and IFN-gamma-modified human melanomas and B16 murine melanoma. Irradiation caused cessation of cell growth and gradual reduction of cell number. Irradiated melanoma cells displayed 1.5 to 10-fold increases in the surface expression of MHC class I and/or class II antigens. The increases in MHC antigens persisted for 7-14 days postirradiation and then declined thereafter. Furthermore, IL-2- and IFN-gamma-transduced melanoma cells showed enhanced expression of the cytokine mRNA and increased cytokine secretion after irradiation. The effect of irradiation on the vaccine potential of the transduced cells was examined in C57BL/ 6 mice by prophylactic immunization and immunotherapy, and in nude mice by mixed transplantation assays. The irradiated, cytokine-transduced B16 cell vaccine was as or more effective than the unirradiated vaccine. These irradiated vaccines protected the animals against a challenging tumorigenic dose of B16 parental cells and suppressed the growth of 4-day-established B16 lung metastases. The ability of the irradiated IL-2-transduced human melanomas to inhibit the growth of admixed parental melanoma cells was retained but was less efficacious than unirradiated cells. The results suggest that irradiation does not abrogate the vaccine potential of IL-2- and IFN-gamma-transduced melanomas. These findings have implications for designing specific active immunotherapy protocols utilizing cytokine gene-modified tumor cells.

Immunological memory induced by genetically transduced tumor cells

BACKGROUND

Recent studies have demonstrated the usefulness of gene-modified tumor cells for immunotherapy. Using the tumorigenic murine fibrosarcoma, MCA 106, we investigated the effects of localized interferon-gamma (IFNg) secretion on tumorigenicity and on long-term memory.

METHODS

The murine IFNg (MuIFNg) gene was introduced into tumor cells. High and low IFNg-secreting clones were isolated. C57BL/6 mice were injected subcutaneously (s.c.) with either parental (P), high or low IFNg-secreting (H- or L-IFNg) cells, and tumor growth was assessed weekly. Spleens were harvested on different days postinjection (p.i.) to assess in vitro cytolytic activity. In parallel, tissues from injection sites were stained with macrophage-, CD4-, and CD8-detecting antibodies. Mice were injected s.c. with H-IFNg MCA106 tumor. After 150 days the animals were rechallenged s.c. with MCA106P in one leg and with irrelevant syngeneic tumor in the other.

RESULTS

Both P- and L-IFNg cells had similar growth, whereas the H-IFNg cells never grew. Only splenocytes from the H-IFNg animals showed in vitro CTL activity persisting until day 30 p.i. Histological data revealed a macrophage and CD4+ infiltrate much earlier in the H-IFNg group compared with the P group. Only the irrelevant, syngeneic tumor grew in animals previously injected with H-IFNg cells, whereas both P and irrelevant syngeneic tumors grew in controls.

CONCLUSIONS

Transduction of MCA106 cells with the MuIFNg gene diminished in vivo tumorigenicity in proportion to the amount of IFNg secreted. Immunization with H-IFNg cells elicited a host response characterized by macrophages and CD4+ cells. Long-term tumor-specific memory was seen after immunization with H-IFNg cells.

Immunotherapy of Human Melanoma With Gene-Modified Tumor Cell Vaccines

The incidence of melanoma in the United States is increasing at a faster rate than that of any other cancer. The prognosis for metastatic disease is poor, and more effective treatments for disseminated disease are needed. Since melanoma is one of the more immunogenic tumors, strategies have focussed on immune recognition. In vitro studies suggest that potent tumor-specific cytotoxic T cells can be induced against human melanoma. Melanoma specific T-cell activation depends on appropriate presentation to the immune system of recently defined melanoma-associated antigens presented in the context of self-HLA gene products. Full T-cell activation requires the co- stimulation by B7-CD28 interactions at the T-cell surface and the elaboration of immune cytokines to promote T-cell growth. Data from animal models of tumor-specific immunization with tumor cells engineered to express immune cytokines or the B7 co-stimulatory molecule suggest that gene therapy for human melanoma may be an effective means to treat disseminated disease.

Metastatic melanoma to the spine. Demographics, risk factors, and prognosis in 114 patients

STUDY DESIGN

One-hundred-fourteen patients with metastatic melanoma of the spine were retrospectively reviewed.

OBJECTIVE

The goal was to define the demographics, risk factors, and prognosis for this population.

SUMMARY OF BACKGROUND DATA

The incidence of melanoma is increasing faster than any other cancer. Therefore, orthopedic and neurologic surgeons will be increasingly confronted by patients with spinal metastases from melanoma. However, the demographics, risk factors, and prognosis remain unclear.

METHODS

From 7010 consecutive patients with melanoma, 114 were identified with clinically or radiographically evident spinal metastases. A comparison was made between these patients and the remainder of the population with melanoma seen at our institution using contingency table analysis with statistical significance determined by a chi-squared test. Survival data were represented by Kaplan-Meier curves, and log-rank testing was used for statistical comparisons.

RESULTS

Risk factors associated with the development of these metastases included primary lesions that were ulcerated, deeper than 0.76 mm, or of Clark level II, or located on the trunk or mucosal surfaces. The median survival time for all patients was 86 days, but this was reduced in patients with more than one metastatic site in addition to the spine.

CONCLUSION

The prognosis for most patients with spinal metastases from melanoma is dismal. However, patients with metastatic disease limited to the spine and one other organ may survive for a relatively prolonged time and may be candidates for surgical intervention directed toward symptomatic relief.

Preoperative radiation and chemotherapy in the treatment of adenocarcinoma of the rectum

OBJECTIVE

In this study, the impact of preoperative chemotherapy and radiation on the histopathology of a subgroup of patients with rectal adenocarcinoma was examined. As well, survival, disease-free survival and pelvic recurrence rates were examined, and compared with a concurrent control group.

SUMMARY BACKGROUND DATA

The optimal treatment of large rectal carcinomas remains controversial; current therapy usually involves abdominoperineal resection plus postoperative chemoradiation; the combination can be associated with significant postoperative morbidity. In spite of these measures, local recurrences and distant metastases continue as serious problems.

METHODS

Fluorouracil, cisplatin, and 4500 cGy were administered preoperatively over a 5-week period, before definitive surgical resection in 43 patients. In this group of patients, all 43 had biopsy-proven lesions > 3 cm (median diameter), involving the entire rectal wall (as determined by sigmoidoscopy and computed tomography scan), with no evidence of extrapelvic disease. The patients ranged from 31 to 81 years of age (median 61 years), with a male:female ratio of 3:1. A concurrent control group consisting of 56 patients (median: 62 years, male:female ration of 3:2) with T2 and T3 lesions was used to compare survival, disease-free survival, and pelvic recurrence rates.

RESULTS

The preoperative chemoradiation therapy was well tolerated, with no major complications. All patients underwent repeat sigmoidoscopy before surgery; none of the lesions progressed while patients underwent therapy, and 22 (51%) were determined to have complete clinical response. At the time of resection, 21 patients (49%) had gross disease, 9 (22%) patients had only residual microscopic disease, and 11 (27%) had sterile specimens. Of the 30 patients with evidence of residual disease, 4 had positive lymph nodes. In follow-up, 39 of the 43 remain alive (median follow-up = 25 months), and only 1 of the 11 patients with complete histologic response developed recurrent disease. Six of the 32 patients with residual disease (2 with positive nodes) have developed metastatic disease in follow-up (median time to diagnosis 10 months, range 3-15 months). Three of these patients with metastases have died (median survival after diagnosis of metastases = 36 months). Local recurrence was seen in only 2 of 43 patients (< 5%). Cox-Mantel analysis of Kaplan-Meier distributions demonstrated increased survival (p = 0.017), increased disease-free survival (p = 0.046), and decreased pelvic recurrence (p = 0.031) for protocol versus control patients.

CONCLUSIONS

This therapeutic regimen has provided enhanced local control and decreased metastases. Furthermore, the marked degree of tumor downstaging, as seen by a 27% incidence of sterile pathologic specimens and a low rate of positive lymph nodes in this group with initially advanced lesions, strongly suggest that less radical surgery and sphincter preservation may be used with increasing frequency.

Transduction of human melanoma cells with interleukin-2 gene reduces tumorigenicity and enhances host antitumor immunity: a nude mouse model

Human melanoma tumor cells were genetically modified in vitro by transferring the interleukin-2 (IL-2) gene via a retroviral vector into established or fresh tumor cells. In addition, human melanoma cells were transduced in vivo by the direct injection of the IL-2/retroviral vector into melanoma xenografts in nude mice. The gene-modified melanoma cells expressed the IL-2 cytokine gene and secreted biologically active IL-2. Transduction of melanoma cells with the IL-2 gene did not affect the antigenic profile of the cells, but caused a strong abrogation of their tumorigenicity. One million parental cells formed subcutaneous tumors in nude mice. In contrast, various doses of up to 20 x 10(6) IL-2-transduced cells failed to form tumor in the mice. Coinjection of IL-2-producing cells with parental cells inhibited tumor formation even when highly tumorigenic doses of parental cells were used. Histochemical analysis of the injection sites of IL-2-modified cells showed an influx of host immune cells, predominantly macrophages, as early as the third day after inoculation. Neutrophils, mast cells, and eosinophils were also seen in the inflammatory exudate. Eventually, transduced cells showed signs of degeneration and necrosis and ultimately died in 4 weeks. Macrophages were seen in parental tumor sites only during the first few days after injection, and then parental tumors exhibited fast, progressive growth. The study suggests that melanoma cells transduced with the IL-2 cytokine gene may provide an effective vaccine for melanoma patients, whereas the in vivo transduction of tumors with cytokine genes is feasible and may represent a novel approach for the immunotherapy of cancer patients.

Transduction of human melanoma cells with the gamma interferon gene enhances cellular immunity

Human tumor cells transduced with the gamma interferon (gamma IFN) gene are currently used in specific active immunotherapy protocols to enhance the antitumor immune responses of cancer patients. This in vitro study was undertaken to examine the initial events in the cellular immune response that may occur following the administration of the gamma IFN-transduced cell vaccine. Human melanoma tumor cell lines were transduced with a MoMLV-based retroviral vector carrying the human gamma IFN gene. The transduced cells expressed the cytokine gene, secreted biologically active gamma IFN, and exhibited enhanced expression of MHC class I and class II (HLA-DR), and ICAM-1 surface antigens. The gamma IFN-transduced and corresponding parental melanoma cells were used for the induction of short-term lymphocyte cultures. Peripheral blood lymphocytes or lymph node cells from 20 melanoma patients were stimulated for 5 to 15 days with autologous or MHC class I-matched allogeneic parental or gamma IFN-transduced melanoma cells. Seven of the 20 lymphocyte cultures showed substantial increases in lytic activity following stimulation with the transduced melanoma cells in comparison to control lymphocyte cultures stimulated with unmodified parental melanoma. The cytolytic activity stimulated with gamma IFN-modified melanomas was mediated partly by MHC-restricted cytotoxic T lymphocytes and partly by NK cells. Lymphocyte cultures that displayed increases in cytotoxicity after stimulation with the gamma IFN-transduced melanoma cells also exhibited enhanced expression or induction of one or more of the following lymphokines: IL-4, IL-1 alpha, IL-1 beta, gamma IFN, and TNF-alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Malignant melanoma in children

BACKGROUND

Cutaneous melanoma is an uncommon malignancy in children and for this reason, there is little information available regarding the timing and patterns of recurrence in children with this disease. This study reviews the experience at a single institution (Duke University Melanoma Clinic) in treating children with malignant melanoma.

METHODS

Eighty-five patients < or = 18 years of age with malignant melanoma have been treated. All but three patients were over the age of 10; 73% of them were > 14. As for adults, treatment consisted of wide local excision of all primary lesions with primary closure or split-thickness skin graft, as needed. In addition, 22 patients underwent dissection of regional lymph nodes. Patients whose tumors had aggressive pathologic characteristics were treated with an adjuvant immunotherapy protocol. Patients with recurrence at distant sites were offered combination chemotherapy.

RESULTS

Patients and pathologic characteristics of sex, race, primary site, histologic type, tumor thickness, and Clark level were similar to those observed in adults. Actuarial survival rates (79% versus 77% at 5 years) of the pediatric and adult Stage I melanoma patients were also not significantly different. Children had a greater incidence of recurrence after initial treatment, although recurrence tended to happen after a longer disease-free interval than for adults. Half of the 79 children who were first seen with Stage I disease have suffered a relapse, but more than one-third were disease free for > or = 5 years after initial treatment. Of the 18 patients who were disease free for > or = 7 years, 12 (67%) ultimately had recurrent disease, including five patients who had recurrences > 13 years after initial diagnosis.

CONCLUSIONS

The early age at which malignant melanoma may occur and the significant potential for very late recurrence mandate that pediatricians and other primary care physicians consider the diagnosis of melanoma even in young patients with new skin lesions and that patients treated for melanoma be carefully followed for a lifetime.

Melanoma of the foot

We performed a prospective study of the results of treatment of primary cutaneous melanoma of the foot in 282 patients to determine if there were any factors that could predict survival. These patients were part of a group of 1018 patients who had primary cutaneous melanoma affecting the lower extremity. We found that 184 (65 per cent) of the 282 patients had a tumor that extended into the reticular dermis or subcutaneous tissue (a Level-IV or V lesion according to the system of Clark et al.). Sixty-three patients (22 per cent) had evidence of local, regional, or distant metastatic disease at the time of presentation. Location of the melanoma on the plantar aspect of the foot was found to be an independent variable that was associated with a poorer rate of survival (56 per cent at five years and 46 per cent at ten years) compared with a dorsally located melanoma (80 per cent at five years and 67 per cent at ten years). Subungual lesions were associated with an extremely low rate of survival (17 per cent at ten years); however, because of the small number of subungual lesions that were followed, the difference in survival between the patients who had a plantar lesion and those who had a subungual lesion was not significant (p = 0.52). Variables, in order of decreasing importance, that had independent prognostic significance for survival of patients who had a melanoma of the foot were the clinical stage of the lesion at the time of presentation (p < 0.001) and the age of the patient (p < 0.03), as determined by multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival superiority of females with melanoma. A multivariate analysis of 6383 patients exploring the significance of gender in prognostic outcome

OBJECTIVE

To evaluate the effects of gender on prognostic outcome of patients with melanoma.

DESIGN

Retrospective cohort study, including 20 years of follow-up.

SETTING

Duke University Melanoma Clinic, Durham, NC, a referral center for patients with melanoma.

PATIENTS

Patients with melanoma (N = 6383), consisting of 45% females and 55% males, obtained from a referred sample. Eligibility requirements were nonocular melanomas and white race.

MAIN OUTCOME MEASURES

Time to metastases and survival.

RESULTS

Females with melanoma demonstrated a superior prognostic outcome over males, with a 34% survival advantage and a 28% disease-free advantage. When each of the variables of age, site, Clark's level, histologic type, and tumor thickness was explored for possible influences on prognostic outcome, female survival advantage persisted, although modified by independent variables. The greatest influence came from the variables of site, Clark's level, and Breslow's thickness. Age, specifically in premenopausal vs postmenopausal age groups, was not significant in altering females' prognostic advantage. A multivariate analysis combining the effects of all the variables resulted in females still maintaining a 22% survival advantage and a 17% disease-free advantage.

CONCLUSIONS

Females with melanoma have a significant prognostic advantage over their male counterparts that cannot be fully explained by influences from the variables of age, site, Clark's level, histology, and Breslow's thickness. This superior prognostic outcome does not appear to be associated with menstrual status. Evidence does suggest that the protective factor for females occurs at the level of metastases.

Surgical management of regional lymph nodes in patients with melanoma. Experience with 4682 patients

OBJECTIVE

The purpose of this study was to evaluate a large number of patients with cutaneous melanoma who had or who were at risk for lymph node metastases to contribute to the understanding of the behavior of and appropriate management of draining nodes. A major goal of the study was to reassess the clinical impact of elective lymph node dissections (ELND) in a large patient population.

SUMMARY BACKGROUND DATA

Large retrospective studies suggest that ELND may improve the prognosis of patients with intermediate thickness melanomas; however, that improvement has not been observed in two randomized prospective controlled trials.

METHODS

The charts of 4682 patients treated at a single institution for localized or regional disease were reviewed individually. The median follow-up was 4.7 years, with 814 patients followed more than 10 years. The data were tabulated and evaluated with the aid of a computer data base system.

RESULTS

Among patients with nodal metastases, 10% of nodal metastases were to contralateral nodes, and 6% were to nodal basins that would not be predicted by classic models of lymphatic drainage; in 13% of patients, nodal metastases occurred to greater than one nodal basin (3% of the entire study group). For all thickness ranges, the incidence of nodal metastases was comparable to the incidence of distant metastases; intermediate-thickness lesions had no relative predilection for nodal metastases. At the initial evaluation, regional nodal basins were clinically negative in 3550 patients, of whom 911 (25.7%) underwent ELND. Stratified into five thickness groups (< 0.76 mm, 0.76 to 1.5 mm, 1.5 to 2.5 mm, 2.5 to 4 mm, and > 4 mm), pathologically positive nodes were identified in 0%, 5%, 16%, 24%, and 36%, respectively (16% overall). Among the 911 patients who underwent ELND, 214 (23%) had nodal metastases, 143 at the time of ELND and 71 at a later date. Of these 71 patients, 31 (44%) had nodal metastases in a previously dissected nodal basin, and 40 (56%) had them in basins not previously dissected. The survival of patients with clinically negative nodes treated with and without ELND were compared. The two groups were well matched for major prognostic factors. Stratified by Breslow thickness and primary site, no significant improvement in survival was observed with ELND.

CONCLUSIONS

Because of the significant incidence of metastases to contralateral and atypical nodal basins, lymphoscintigraphy may be justified for the preoperative evaluation of patients for ELND. However, the therapeutic value of ELND is questionable as a result of (1) the finding that the risk of nodal metastases is not relatively more common than is that of distant metastases among patients with intermediate-thickness melanomas, (2) the fact that only 16% of ELND were positive, (3) the finding that ELND may not prevent recurrent nodal disease in the dissected basin, and (4) the absence of any apparent impact on survival among patients who underwent ELND.

Elevation of topoisomerase I messenger RNA, protein, and catalytic activity in human tumors: demonstration of tumor-type specificity and implications for cancer chemotherapy

Topoisomerase I has been identified as an intracellular target of camptothecin, a plant alkaloid with anticancer activity. Various lines of evidence suggest that the sensitivity of cells to this drug is directly related to the topoisomerase I content. In humans, the levels of topoisomerase I have been shown to be elevated in colorectal tumors, compared to normal colon mucosa. The aim of our study was to determine whether (a) topoisomerase I levels are elevated in other solid tumors, (b) the elevated enzyme is catalytically active in these tumors, and (c) the increase in topoisomerase I levels in colorectal tumors is a result of increased transcription or translation. Topoisomerase I levels were quantitated in crude extracts from colorectal, prostate, and kidney tumors and their matched normal counterparts by Western blotting and by direct determination of catalytic activity, and mRNA levels were determined by Northern blotting. By Western blotting, colorectal tumors showed 5-35-fold increases in topoisomerase I levels, compared to their normal colon mucosa. In the case of prostate tumors, the increase was 2-10-fold, compared with benign hyperplastic prostate tissue from the same patients. However, no difference was observed in topoisomerase I levels in kidney tumors, compared to their normal counterparts. The catalytic activity of topoisomerase I was determined by a quantitative 32P-transfer assay in crude homogenates, without isolating nuclei. Colorectal and prostate tumors exhibited 11-40- and 4-26-fold increases, respectively, in catalytic activity. However, kidney tumors did not show any alteration in catalytic activity, compared to their normal matched samples. Thus, for all three tumor types there was a good correlation between enzyme levels and catalytic activity. Finally, colorectal tumors were analyzed for steady state mRNA levels. A 2-33-fold increase in mRNA levels was found in colorectal tumors, compared to normal colon mucosa. These results suggest that alterations in topoisomerase I expression in humans are tumor type specific and that the increase in topoisomerase I levels results from either increased transcription of the topoisomerase I gene or increased mRNA stability.

Cell surface reactive human monoclonal antibody directed to human melanoma-associated gangliosides

An IgM human monoclonal antibody (human MAb) was generated by fusing lymph node cells isolated from a surgical specimen of malignant melanoma with the heteromyeloma cell line SHMD-33. The antibody, designated 7c11.e8, reacted with surface antigens on human melanoma cells as shown by live cell immunofluorescence and absorption assays. The MAb 7c11.e8 reacted with DSI, SPG, GM4, GM3 and GD3 in enzyme-linked immunosorbent assays (ELISA), and did not react with GD2, GM1, GM2, GD1a, GD1b, GT1b and a number of neutral glycosphingolipids. The main binding epitope for the MAb was, therefore, the terminal N-acetylneuraminic acid 2-3 Gal linked by a beta 1-1 bond to the ceramide, or a beta 1-4 bond to glucose or glucosamine. As shown by immunohistochemical assays, 7c11.e8 antigen was expressed on all melanoma tumour tissues, and on a few samples of colon carcinoma, normal colon, skin, spinal cord, kidney and liver. However, other normal organs such as breast, lung, small intestine, stomach and lymph nodes did not react with the MAb. In the presence of human serum the antibody initiated a strong lysis of melanoma tumour cells in complement-dependent cellular cytotoxicity (CDCC) assays. This study demonstrates that it is possible to isolate human monoclonal antibodies directed to cell surface antigens using viable cell assays in the screening protocol. The preferential binding of 7c11.e8 to melanoma tissues and the reactivity with two of the major melanoma gangliosides (GM3 and GD3) suggest that 7c11.e8 may provide a useful reagent for diagnosis and therapy of malignant melanoma.