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Biomedical subjects

G J Bosl

Publications and source records attributed to G J Bosl.

At least 19 recordsLinked to original sources
PubMed1995

Salvage laryngectomy for unsuccessful larynx preservation therapy.

From 1983 to 1991, 31 patients underwent salvage laryngectomy for persistent or recurrent squamous carcinoma of the larynx (14), hypopharynx (15), or oropharynx (2) as part of a larynx preservation protocol. Laryngectomy was performed as a consequence of poor response to induction chemotherapy in 13 and for recurrent disease after completion of chemotherapy and irradiation in 18. Postoperative pharyngocutaneous fistula occurred in 39%, resulting in prolonged hospitalization. Local control was achieved in 68%, more often in patients with laryngeal as opposed to nonlaryngeal primaries (86% versus 53%; p = .05). The overall actuarial survival and disease-specific survival at 2 years were 32% and 38%, respectively. Disease-specific survival at 2 years was better in patients with laryngeal as compared to nonlaryngeal primaries (56% versus 24%; p = .02). There were no long-term survivors among the nonlaryngeal primary patients. In selected patients in whom larynx preservation failed, salvage laryngectomy was associated with acceptable local control and survival. Palliation was obtained in patients who were not cured by their laryngectomy. Future investigation will focus on identification of factors predicting complications and strategies to reduce the incidence and severity.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Molecular and cytogenetic studies in the diagnosis of patients with poorly differentiated carcinomas of unknown primary site.

PURPOSE: A minority of patients with poorly differentiated carcinoma achieve a complete response to cisplatin therapy. Recently, specific chromosomal abnormalities have been described for several solid tumor malignancies. Molecular and cytogenetic techniques were used to study tumors of patients with midline carcinoma of unknown primary site. MATERIALS AND METHODS: Forty patients with poorly differentiated carcinoma of unknown primary site had fresh tumor samples studied by cytogenetic analysis, Southern blot analysis for 12p copy number, and fluorescence in situ hybridization (FISH) for the identification of i(12p) and chromosome 12 aneuploidy. The response to cisplatin therapy was correlated to the diagnosis provided by the genetic studies. RESULTS: In 17 (42%) patients, a diagnosis was suggested by the genetic studies. This included a germ cell tumor in 12 (30%) patients by the finding of i(12p), increased 12p copy number, or a deletion of the long arm of chromosome 12. In five patients, a specific diagnosis other than germ cell tumor was suggested by tumor karyotype. These were neuroepithelioma, lymphoma, desmoplastic small-cell tumor, melanoma, and clear-cell sarcoma. The 75% response proportion to cisplatin therapy in patients with tumors showing chromosome structural abnormalities of germ cell tumor was greater than the 18% response proportion in patients for whom no diagnosis was provided (P = .002). CONCLUSION: Molecular and cytogenetic studies are useful in establishing specific diagnoses in patients with poorly differentiated carcinomas of unknown primary site. This group of tumors is heterogeneous and is composed of germ cell tumors, melanoma, lymphoma, neuroepithelioma, and desmoplastic small-round-cell tumor in addition to some that are not yet classifiable. Response to cisplatin therapy correlates with the finding of i(12p) in tumor by either molecular or cytogenetic studies.

Adenocarcinoma↗
PubMed1995

Recombinant human granulocyte-macrophage colony-stimulating factor as an adjunct to conventional-dose ifosfamide-based chemotherapy for patients with advanced or relapsed germ cell tumors: a randomized trial.

PURPOSE: Ifosfamide-containing therapy with cisplatin plus either etoposide (VIP) or vinblastine (VeIP) can cure of patients with relapsed germ cell tumors (GCTs), but results in substantial myelotoxicity. This study sought to assess the impact of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on the severity of neutropenia and incidence of infectious complications in patients who receive ifosfamide-based chemotherapy for GCT. PATIENTS AND METHODS: One hundred and four assessable GCT patients from 20 centers were randomized to receive rhGM-CSF with either cycles 1 and 2 or cycles 3 and 4 of chemotherapy. Standard doses of VIP or VeIP were used. Efficacy data were analyzed using a parallel design for cycles 1 and 2 before the crossover. RESULTS: Fewer clinically relevant infections occurred in rhGM-CSF patients (13 of 55, 24%) versus observation patients (22 of 49, 45%) in cycle 1 (P = .01). Decreases were observed in infections during neutropenia (22% v 43%, P = .03), infections requiring intravenous antibiotics (20% v 43%, P = .01), and any infection irrespective of severity (29% v 55%, P = .01) in cycle 1. However, there were no significant differences among the treatment arms in cycle 2 in the proportion of clinically relevant infections (P = .23), infections associated with neutropenia (P = .11), infections requiring antibiotics (P = .22), or any infection (P = .65). rhGM-CSF was discontinued in 14% of cycles because of toxicity related to the growth factor. CONCLUSION: rhGM-CSF reduced the incidence of infections in the first cycle of chemotherapy, but no benefit beyond the initial chemotherapy cycle was evident. Based on the limited clinical impact and the high incidence of rhGM-CSF-related toxicity that required growth factor discontinuation, the routine administration of rhGM-CSF to prevent neutropenia and infection after ifosfamide-based chemotherapy for GCT patients is not recommended.

Adolescent↗
PubMed1995

Etoposide and cisplatin adjuvant therapy for patients with pathologic stage II germ cell tumors.

PURPOSE: Two options cure nearly all patients with pathologic stage II nonseminomatous germ cell tumors (NSGCTs): two cycles of adjuvant chemotherapy with cisplatin, vinblastine, and bleomycin (PVB) or cisplatin, vinblastine, bleomycin, cyclophosphamide, and dactinomycin (VAB-6); or close observation with full treatment at relapse. Two cycles of etoposide plus cisplatin (EP) were given to selected patients with pathologic stage II NSGCT and high-volume nodal metastases. PATIENTS AND METHODS: All patients had pathologic stage II NSGCT with one or more of the following features found at retroperitoneal lymph node dissection (RPLND), suggesting a greater than 50% likelihood of relapse after observation alone: (1) any lymph node involved by tumor greater than 2 cm (stage N2b); (2) > or = six nodes involved with tumor (stage N2b); and (3) extranodal extension (stage N3). Two cycles of therapy were given at 21-day intervals; each cycle consisted of etoposide 100 mg/m2 plus cisplatin 20 mg/m2 per day given on days 1 to 5. RESULTS: Fifty patients were treated with two cycles of EP. Treatment was well tolerated; five patients (10%) were admitted for nadir fever and none had grade II or greater neurologic, renal, or pulmonary toxicity. All 50 patients are alive and relapse-free at a median follow-up time of 35 months (range, 12 to 72). The follow-up duration has been > or = 2 years for 42 patients. CONCLUSION: A treatment program that consists of two cycles of EP is effective in preventing relapses in patients with completely resected pathologic stage N2b and N3 NSGCT. The likelihood of relapse without adjuvant cisplatin-containing chemotherapy in this group has been shown to be greater than 50%. As has been demonstrated in patients with disseminated germ cell tumor (GCT), EP can be considered a therapeutic option in the adjuvant setting for completely resected N2b and N3 NSGCT.

Adolescent↗
PubMed1995

Paclitaxel in germ cell cancer.

The teratocarcinoma cell line 833K and its relatively cisplatin-resistant subline 833K/63CP 10 were used to assess the cytotoxicity of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), cisplatin, and 4-hydroxyperoxycyclophosphamide quantitatively. The results showed that paclitaxel had marked cytotoxicity against teratocarcinoma, particularly in the cells that were relatively cisplatin resistant. These studies suggested synergy in cytotoxicity for paclitaxel, cisplatin, and 4-hydroxyperoxycyclophosphamide. A phase II trial of paclitaxel was conducted in patients with previously treated germ cell tumors with restricted prior treatment. The paclitaxel dose was 250 mg/m2 given by 24-hour continuous infusion. In 31 patients treated with paclitaxel, eight (26%) achieved a major (complete or partial) response. The antitumor activity of paclitaxel in the phase II trial has led us to further study it as a part of combination therapy. Since the in vitro studies showed synergistic cytotoxicity, combination studies of paclitaxel, ifosfamide, and platinum are under way as salvage treatment for patients with germ cell tumors.

Adolescent↗
PubMed1994

Platinum-DNA adducts assayed in leukocytes of patients with germ cell tumors measured by atomic absorbance spectrometry and enzyme-linked immunosorbent assay.

BACKGROUND: Platinum-DNA adducts can be measured in peripheral blood cells, and high adduct levels have previously been correlated with favorable clinical response to platinum-based therapy in patients with germ cell tumors and ovarian cancer. METHODS: To evaluate the relationship between platinum-DNA adducts and clinical response to chemotherapy, 36 patients with germ cell tumors treated with cisplatin-based chemotherapy had platinum-DNA adducts assayed in leukocytes by atomic absorption spectrometry (AAS) and cisplatin-DNA enzyme-linked immunosorbent assay (ELISA). Three chemotherapy regimens were involved: cisplatin and etoposide (Regimen A); carboplatin and etoposide (Regimen B); and cyclophosphamide, vinblastine, dactinomycin, bleomycin, and cisplatin [VAB-6] with or without high dose carboplatin plus etoposide plus autologous bone marrow rescue (Regimen C). Blood samples were drawn before and after each cycle of chemotherapy. RESULTS: One hundred ninety-two blood samples were assayed by AAS and 137 by ELISA: DNA adducts measured by AAS and ELISA increased immediately after treatment and decreased during the intervening time before the next treatment. DNA adducts were measurable by both methods 4-8 weeks after the last cycle of therapy. The peak and mean adduct levels measured in samples drawn immediately after Cycles 1 and 2 and after all cycles were analyzed in terms of their relationship to clinical response. In contrast to numerous prior studies, a positive correlation was not observed between DNA adduct formation as determined by either AAS or ELISA and favorable clinical responses. CONCLUSIONS: This study demonstrated that peak and mean platinum-DNA adduct levels were influenced by the dose and schedule of the platinum analogue. For example, treatment with VAB-6 with or without high dose carboplatin and etoposide (Regimen C) resulted in significantly higher adduct levels when measured by AAS compared with Regimen A or B. Inconsistencies between studies regarding observed correlations of DNA adducts and treatment outcome may be attributable to differences in platinum analogue, dose, schedule, and timing of sample procurement. These factors must be considered in future studies.

Adolescent↗
PubMed1994

Serum tumor marker decline is an early predictor of treatment outcome in germ cell tumor patients treated with cisplatin and ifosfamide salvage chemotherapy.

BACKGROUND: Serum tumor marker regression (alpha-fetoprotein [AFP] and human chorionic gonadotrophin [hCG]) was studied in patients treated with ifosfamide-based chemotherapy for cisplatin-resistant germ cell tumors (GCT) to investigate the role of marker regression as a predictor of treatment outcome. METHODS: Fifty-four patients treated with cisplatin and ifosfamide-containing therapy were the subject of this retrospective analysis. The serum tumor marker half-life (T1/2) for the first two cycles of therapy was calculated for each patient using all marker values Day 7 through the end of the second treatment cycle. A calculated T1/2 for hCG of less than or equal to 3 days or a calculated T1/2 for AFP of less than or equal to 7 days was defined as appropriate marker regression; any T1/2 greater than these values was considered prolonged. A variable designated "marker decline" was defined to indicate whether the serum tumor marker half-life of AFP and/or hCG was satisfactory or unsatisfactory for each individual patient. Both univariate and multivariate analyses were conducted to investigate "marker decline" as a predictor for response, event-free survival (time to death or relapse), and overall survival. RESULTS: Satisfactory marker decline predicted an improved event-free survival and overall survival. The median event-free survival for patients with an unsatisfactory marker decline was 5.8 months versus 20.7 months for patients with a satisfactory marker decline. Survival for patients with an unsatisfactory marker decline was 6.3 months versus 20.7 months for those patients with a satisfactory marker decline. Further evaluation demonstrated that hCG decline was a stronger predictor for improved survival than AFP decline. A multivariate analysis performed on selected clinical variables using a Cox regression model demonstrated that marker decline, pretreatment hCG, and primary site were independent predictors for event-free and overall survival. CONCLUSIONS: The rate of serum AFP and/or hCG decline during the first two cycles of therapy was predictive for event-free and overall survival in GCT patients treated with ifosfamide-based salvage therapy. Those patients with an appropriate serum tumor marker decline had a longer event-free and overall survival. When evaluated separately, the rate of hCG decline was more predictive of treatment outcome than decline of AFP. The rate of serum tumor marker regression during the first two cycles of therapy is a clinically useful tool in assessing treatment outcome at an early point in therapy and may thereby identify patients who could benefit from a change to more intensive therapy.

Biomarkers, Tumor↗
PubMed1994

The management of patients with nonseminomatous germ cell tumors of the testis with serologic disease only after orchiectomy.

Management of patients with nonseminomatous germ cell tumors of the testis who have persistently elevated serum tumor marker levels (alpha-fetoprotein and/or human chorionic gonadotropin) following orchiectomy and no clinical evidence of disease is controversial. We reviewed our experience with 15 such patients at our cancer center between March 1977 and November 1991. Group 1 (11 patients) underwent initial retroperitoneal lymph node dissection and group 2 (4 patients) received primary chemotherapy. All group 1 patients required subsequent chemotherapy for retroperitoneal disease or persistent marker elevation, whereas only 1 of the 4 who received primary chemotherapy required later surgery. We conclude that tumor marker elevation in this setting is usually indicative of systemic tumor, which is best treated primarily by initial chemotherapy.

Adult↗
PubMed1994

Serum tumor marker half-life during chemotherapy in patients with germ cell tumors.

Approximately 80% of previously untreated men with metastatic germ cell tumors will be cured with cisplatin-based chemotherapy. Serum levels of alpha fetoprotein (AFP) or human chorionic gonadotropin (HCG) or both are increased in most of these patients. Pre-treatment clinical characteristics can be used to distinguish between "good" and "poor" risk patients who are either highly likely or unlikely to achieve a complete remission, respectively. A slow rate of decline of either AFP or HCG or both has been associated with an inferior survival in both good and poor risk patients. In multivariate analysis, the pre-treatment risk status and the post-treatment clearance of markers were independent and equal prognostic variables. Similarly, in patients receiving cisplatin+ifosfamide-based salvage chemotherapy, the rate of decline of HCG was an independent predictor variable in addition to the primary site and pre-treatment HCG levels for both overall and event-free survival. Prolonged half-life clearance of serum tumor markers is an important prognostic variable in both previously untreated as well as previously treated germ cel tumor patients. Treatment strategies can be based on marker clearance and prospective clinical trials are warranted.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Advanced seminoma: treatment results, survival, and prognostic factors in 142 patients.

PURPOSE: To investigate the efficacy of chemotherapy and to assess the relationship between selected pretreatment characteristics and survival in patients with advanced seminoma. PATIENTS AND METHODS: One hundred forty-two patients with advanced seminoma treated with platinum-based chemotherapy were the subject of this study. Treatment regimens included cisplatin, vinblastine, bleomycin, cyclophosphamide, and dactinomycin (VAB-6) (45 patients), a six-cycle regimen of VAB-6 alternating with etoposide and cisplatin (two patients), cisplatin and etoposide (60 patients), and etoposide and carboplatin (35 patients). RESULTS: One hundred thirty of 140 (93%) assessable patients treated with platinum-based therapy achieved a favorable response (complete response or a partial response with negative serum tumor markers). One hundred twenty-five patients (88%) are alive and 120 (86%) remain progression-free at a median follow-up duration of 43 months. Fifty-seven of 60 patients (95%) who were treated with cisplatin and etoposide achieved a favorable response; 55 (92%) remain progression-free. The relative risks of death or of an event (death or relapse) related to human chorionic gonadotropin (HCG) elevation were 1.8 (P = .04) and 1.96 (P = .001), respectively. The relative risks of death or of an event associated with lactate dehydrogenase (LDH) elevation were 2.6 (P = .05) and 2.7 (P = .02), respectively. All 19 patients with a mediastinal primary tumor site achieved a complete response, and 18 of 19 (95%) remain progression-free. CONCLUSION: Four cycles of cisplatin and etoposide is highly effective therapy for seminoma and is the standard therapy at our center. Elevation of the serum markers HCG and LDH were of prognostic significance, while an extragonadal primary tumor site was not associated with an adverse prognosis. Studies of tumor biology, including genetic analysis, are ongoing to determine other parameters that may correlate with response and survival.

Adolescent↗
PubMed1994

Phase II trial of paclitaxel shows antitumor activity in patients with previously treated germ cell tumors.

PURPOSE: A trial of paclitaxel was conducted in patients with previously treated germ cell tumors (GCT). As the identification of new agents in GCT may be compromised by restricting entry criteria to heavily pretreated patients, an alternative trial design was used in which eligibility was restricted to patients with limited prior therapy. PATIENTS AND METHODS: Patients were eligible if their prior therapy was limited to one cisplatin-based regimen or < or = six cycles of prior cisplatin-based therapy. Paclitaxel 250 mg/m2 was administered by continuous infusion over 24 hours every 21 days. The dose of paclitaxel was modified for each patient based on toxicity. Granulocyte colony-stimulating factor (G-CSF) 5 micrograms/kg/d was administered during nadir periods. RESULTS: Thirty-one patients were treated; eight patients (26%) achieved a partial (n = 5) or a complete (n = 3) response. Responses were achieved in patients who had failed to respond to treatment with cisplatin, ifosfamide, and etoposide, and in patients with poor prognostic features, ie, mediastinal primary tumor site and patients with a best prior response of an incomplete response to cisplatin therapy. One complete responder remains continuously free of disease at 13+ months and one of the five patients who achieved a partial response remains progression-free at 14+ months. CONCLUSION: Paclitaxel has antitumor activity in GCT and warrants continued study in combination chemotherapy. Phase I/II trials will address its role in combination with cisplatin and ifosfamide and as a part of dose-intensive therapy. Furthermore, the study showed that a trial design in which eligibility criteria limits prior therapy was feasible, resulted in the identification of antitumor activity in a new agent, and may be considered in future trials for other promising new agents in GCT.

Adolescent↗
PubMed1994

After a treatment breakthrough: a comparison of trial and population-based data for advanced testicular cancer.

PURPOSE: To determine to what extent the benefits of cisplatin-based combination chemotherapy have been disseminated to all American men diagnosed with advanced testicular cancer. PATIENTS AND METHODS: One hundred seventy-two advanced testicular cancer cases from five population-based registries of the Surveillance, Epidemiology, and End Results (SEER) Program diagnosed from 1978 to 1984 were compared with 133 diagnostically comparable cases from the Memorial Sloan-Kettering Cancer Center (MSKCC) vinblastine, dactinomycin, and bleomycin (VAB) regimens 7 through 9. Exclusions were made in both series for cases with elevated markers only, abdominal disease only, or extragonadal tumors. Ratings of extent of disease using the Indiana University system (minimal/moderate or advanced) were available for the MSKCC cases, and were determined retrospectively on the SEER cases based on information abstracted from medical records. RESULTS: Among the SEER cases, 89% reported receiving chemotherapy, and 95% of these received cisplatin-containing regimens. Survival among the MSKCC patients was significantly better than for the SEER cases in the minimal/moderate extent of disease category (95% and 73% 3-year survival rate, respectively); however, the difference for advanced cases was only marginally significant (52% and 40% 3-year survival rates, respectively). Survival did not vary significantly by year of diagnosis in either series. CONCLUSION: Although most of the patients in the SEER series received cisplatin-based chemotherapy, this alone did not produce results equivalent to that in the MSKCC series. Since the patients were selected to be as diagnostically comparable as possible at baseline, remaining differences in survival may be due to adherence to a fixed regimen and level of dose-intensity, adequacy of diagnostic work-up, implementation of salvage therapies and debulking surgery, and unknown factors related to who is willing and able to travel to a tertiary care center for treatment. Whatever the reason for not achieving optimal results in the SEER series, the very modest survival improvements over the time period 1978 to 1984 indicates that the differences in outcome between the two series were basically stable over the study period.

Adolescent↗
PubMed1994

Allelic loss and somatic differentiation in human male germ cell tumors.

The complex but poorly understood human male germ cell tumors offer unusual opportunities for the genetic analysis of malignant transformation and embryonal differentiation in a pluripotential stem cell lineage. Histologically, these tumors are divided into two major subgroups, seminomas which are characterized by inability to express embryonal differentiation, and non-seminomas which are characterized by ability to express embryonal as well as extra-embryonal patterns of differentiation. To understand the role of genetic factors in the development of these tumors and the regulation of differentiation expressed by them, we carried out a detailed allelotype analysis by the loss of heterozygosity assay. This analysis revealed frequent deletions in known tumor suppressor genes (RB1, DCC, NME), a number of previously described sites of candidate tumor suppressor genes (3p, 9p, 9q, 10q, 11p, 11q and 17p), as well as several novel sites (2p, 3q, 5p, 12q, 18p and 20p). Our results also showed that well differentiated teratomas exhibit a significantly higher level of allelic loss compared to the less differentiated embryonal carcinomas. In addition, certain loci and genes exhibited frequent non-random deletion in teratomas (D3S32, D3S42, D5S12, D10S25, D11S12, RB1, TP53, NME1, NME2, D17S4, D18S6 and D20S6) and embryonal carcinomas (IFNB, D9S27). Among these loci, the NME genes were notable for a high degree of genetic loss (> 70%) in teratomas. These results suggested that nonrandom loss or inactivation of certain genes may be associated with tumor development and loss or inactivation of other genes may be associated with somatic differentiation.

Alleles↗
PubMed1993

Phase II trial of high-dose carboplatin and etoposide with autologous bone marrow transplantation in first-line therapy for patients with poor-risk germ cell tumors.

BACKGROUND: Between 20% and 30% of patients with advanced germ cell tumors (GCTs) fail to have durable complete response to conventional cisplatin-based induction chemotherapy. However, third-line therapy with high-dose carboplatin and etoposide plus autologous bone marrow transplantation (AuBMT) has induced durable complete response in 10%-20% of patients with cisplatin-resistant GCT. PURPOSE: We conducted a phase II trial of first-line therapy that included high-dose carboplatin and etoposide plus AuBMT in untreated men with advanced GCTs and unfavorable prognosis (i.e., "poor-risk" patients). METHODS: Twenty-eight patients were treated with a conventional-dose, cisplatin-containing regimen (VAB-6 [cisplatin, vinblastine, bleomycin, cyclophosphamide, dactinomycin]) with or without high-dose carboplatin (1500 mg/m2) and etoposide (1200 mg/m2) plus AuBMT. Twenty-two of these patients were selected for treatment with two cycles of high-dose carboplatin and etoposide plus AuBMT when reduced clearance of serum tumor markers (alpha-fetoprotein [AFP] or human chorionic gonadotropin [HCG]), as evidenced by prolonged half-life (> 7 days for AFP and > 3 days for HCG), was observed after two cycles of conventional treatment. RESULTS: Fifteen (56%) of 27 patients considered assessable for response achieved a complete response (12 treated with high-dose chemotherapy plus AuBMT). Sixteen (57%) are alive; 13 (46%) are free of disease at a median follow-up of 31.2 months. For 36 cycles of high-dose chemotherapy, the median duration from bone marrow infusion until a granulocyte count of 0.5/mm3 and a platelet count of 50,000/mm3 was 16 days (range, 7-41 days and 8-30 days, respectively). Analysis showed a trend toward improved survival (P = .07) in patients treated with high-dose chemotherapy in this study, compared with 68 poor-risk patients with GCT treated with conventional-dose therapy alone in two earlier studies. Toxicity was not cumulative, and recovery of blood counts after AuBMT was generally rapid. CONCLUSIONS: Inclusion of high-dose carboplatin-containing chemotherapy in treatment of poor-risk GCT patients is feasible when serum tumor marker half-life is used to predict resistance to standard cisplatin-based therapy. High-dose therapy in this setting was well tolerated. IMPLICATIONS: Early use of a dose-intensive regimen may increase survival compared with conventional-dose therapy alone. Further studies with standard induction therapy and intensive high-dose therapy using hematopoietic growth factor support are warranted, followed by a randomized trial comparing this strategy with standard therapy.

Adolescent↗
PubMed1993

Molecular cytogenetic analysis of i(12p)-negative human male germ cell tumors.

The i(12p) chromosome has been shown to characterize more than 80% of male germ cell tumors (GCTs) and is an important diagnostic marker. Although recent cytogenetic analyses of GCTs have defined nonrandom chromosome abnormalities in these tumors, no attempt has so far been made to compare i(12p)-positive and -negative tumors in terms of their cytogenetic, histologic, and clinical features. During a 5-year period, we have ascertained 202 GCTs, of which 117 had clonally abnormal karyotypes. Among the latter, 91 had one or more copies of i(12p), whereas 26 lacked an i(12p). We report here the karyotypic analysis of these 26 i(12p)-negative GCTs. In this group, nonrandom sites of chromosomal rearrangements included 12p13 (9/26) and 1p11-q11 (5/26). Comparison of the cytogenetic features of i(12p)-negative tumors with i(12p)-positive tumors revealed the only significant difference to be rearrangements affecting 12p13 in the former (35%) as compared to their absence in the latter (3%). Hybridization of metaphase preparations of 9 i(12p)-negative tumors with a chromosome 12 painting probe and with a microdissected 12p painting probe revealed extra copies of chromosome 12 segments incorporated into marker chromosomes whose composition could not otherwise be resolved by banding analysis; all were shown to be derived from 12p. These data demonstrate that both i(12p)-negative and -positive groups are characterized by an increased copy number of 12p, which is consistent with a lack of significant clinical or biological difference between them. An increased 12p copy number thus is a specific aberration of significance to the development of germ cell tumors.

Chromosome Aberrations↗