Risk Factors for Eribulin-induced Severe Neutropenia in Patients With Recurrent Breast Cancer.

BACKGROUND/AIM: Eribulin is an effective chemotherapeutic agent for advanced and metastatic breast cancer. However, severe neutropenia occurs in 30-40% of patients and interferes with the recommended treatment schedule. Neutropenia is a major cause of treatment interruptions, delays, or even relative dose reductions. This study aimed to examine the risk factors for severe neutropenia after eribulin treatment. PATIENTS AND METHODS: We retrospectively evaluated 263 patients with metastatic breast cancer who had received eribulin therapy. Risk factors for severe neutropenia in the first cycle were evaluated. RESULTS: Severe neutropenia in cycle 1 occurred in 50% of the patients. Multivariate analysis suggested six risk factors for severe neutropenia: low baseline neutrophil count and body mass index, high aspartate aminotransferase and bilirubin levels, creatinine clearance (CrCl) less than 50 ml/min, and eribulin dose of 1.4 mg/m2 Conclusion: This is one of the few studies to simultaneously examine both hepatic and renal functions in relation to severe neutropenia induced by eribulin. We have provided important information to support the close monitoring of patients with these risk factors and subsequent dosage adjustments, if necessary.

Efficacy, safety, and biomarker analysis of nivolumab in combination with abemaciclib plus endocrine therapy in patients with HR-positive HER2-negative metastatic breast cancer: a phase II study (WJOG11418B NEWFLAME trial).

BACKGROUND: Hormone receptor (HR)-positive breast cancer is a disease for which no immune checkpoint inhibitors have shown promise as effective therapies. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors synergistically increased the effectiveness of antiprogrammed cell death protein-1 (anti-PD-1)/programmed death-ligand 1 (PD-L1) antibodies in preclinical studies. METHODS: This non-randomized, multicohort, phase II study evaluated the efficacy and safety of the anti-PD-1 antibody nivolumab 240 mg administered every 2 weeks in combination with the CDK4/6 inhibitor abemaciclib 150 mg twice daily and either fulvestrant (FUL) or letrozole (LET) as a first-line or second-line treatment for HR-positive HER2-negative metastatic breast cancer. The primary end point was the objective response rate (ORR), and secondary end points were toxicity, progression-free survival, and overall survival. Blood, tissue, and fecal samples were collected at multiple points for correlative studies to evaluate immunity biomarkers. RESULTS: From June 2019 to early study termination due to safety concerns on July 2020, 17 patients were enrolled (FUL: n=12, LET: n=5). One patient with a prior treatment history in the FUL cohort was excluded. ORRs were 54.5% (6/11) and 40.0% (2/5) in the FUL and LET cohorts, respectively. Treatment-emergent (TE) adverse events (AEs) of grade ≥3 occurred in 11 (92%) and 5 (100%) patients in the FUL and LET cohorts, respectively. The most common grade ≥3 TEAEs were neutropenia (7 (58.3%) and 3 (60.0%) in the FUL and LET cohorts, respectively), followed by alanine aminotransferase elevation (5 (41.6%) and 4 (80.0%)). One treatment-related death from interstitial lung disease occurred in the LET cohort. Ten patients developed liver-related grade ≥3 AEs. Liver biopsy specimens from 3 patients showed hepatitis characterized by focal necrosis with predominant CD8+ lymphocyte infiltration. Marked elevation of tumor necrosis factor-related cytokines and interleukin-11, and a decrease in peripheral regulatory T cells (Tregs), were observed in patients with hepatotoxicity. These findings suggest that treatment-related toxicities were immune-related AEs likely caused by proinflammatory cytokine production and suppression of Treg proliferation due to the addition of abemaciclib to nivolumab therapy. CONCLUSIONS: Although the combination of nivolumab and abemaciclib was active, it caused severe and prolonged immune-related AEs. TRIAL REGISTRATION NUMBER: JapicCTI-194782, jRCT2080224706, UMIN000036970.

Real-World Predictors of Severe Neutropenia Associated with Palbociclib and Endocrine Therapy for Metastatic Breast Cancer in Japanese Patients.

Therapy for patients of metastatic breast cancer based on palbociclib, a cyclin-dependent kinase 4/6 inhibitor, has been approved in Japan. However, the risk factors for palbociclib-induced severe neutropenia in Japanese patients are rarely reported. Hence, the present study is aimed to identify the risk factors for adverse events requiring palbociclib dose reduction or discontinuation, and to identify the factors necessary to identify a more stable strategy for treatment continuation. This retrospective cohort analysis included patients with advanced breast cancer treated with 125 mg/d palbociclib. We demonstrated that severe neutropenia required significant dose reduction or therapy cessation. Most (77%) of the patients had severe neutropenia within the three courses. Risk factors for grade 3 or higher included low neutrophil counts (< 3250 /µL) before treatment [odds ratio (OR) = 9.10, 95% confidence interval (CI) (2.80-29.41), p < 0.001] and high age-adjusted Charlson comorbidity index (> 9) [OR = 1.64, 95% CI (1.09-2.48), p = 0.018]. Thus, low baseline neutrophil counts and high values for Age-adjusted Charlson comorbidity index are prospective predictive markers for palbociclib-induced severe neutropenia.

Clinical Management of Potential Toxicity of Abemaciclib and Approaches to Ensure Treatment Continuation.

INTRODUCTION: The association between abemaciclib dose reduction and treatment adherence is not clear. In this study, we examined real-world data of Japanese patients with advanced breast cancer (ABC) to determine how abemaciclib dose reduction is related to treatment continuation. METHODS: This retrospective observational study involved 120 consecutive patients with ABC who received abemaciclib from December 2018 to March 2021. The time to treatment failure (TTF) was estimated using the Kaplan-Meier method. Univariate and multivariate analyses were performed to identify factors associated with a TTF of >365 days (TTF365). RESULTS: According to the dose reduction during treatment, the patients were classified into 100, 200, and 300 mg/day abemaciclib groups. The 300 mg/day group had a TTF of 7.4 months, whereas the 100 and 200 mg/day groups had significantly longer TTFs (17.9 and 17.3 months, respectively; P = 0.0002). In this study, relative to the 300 mg/day arm, TTF was improved in 200mg/day arm and 100 mg/day arm (hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.33-0.93) and [HR], 0.37; 95% CI, 0.19-0.74). For patients who received 300mg/day of abemaciclib dose arm, 200mg/day, and 100mg/day, the median TTF was 7.4 ,17.9 and 17.3 months. The frequently reported adverse effects (AEs) were anemia, increased blood creatinine levels, diarrhea, and neutropenia (90%, 83%, 83%, and 75% of the patients, respectively). Neutropenia, fatigue, and diarrhea were the top AEs causing dose reduction. A multivariate analysis that examined factors associated with achieving TTF 365 confirmed that dose down was an important factor (odds ratio: 3.95, 95% confidence interval: 1.68-9.36, P = 0.002). CONCLUSIONS: In this study, the 100 and 200 mg/day groups had a longer TTF than the 300 mg/day group, and dose reduction was identified as an important factor in achieving longer TTF.

Programmed death ligand 1-positive immune cells in primary tumor or metastatic axillary lymph nodes can predict prognosis of triple-negative breast cancer even when present at < 1% in the tumor region.

BACKGROUND: The efficacy of pre-operative systemic treatment (PST) combined with immune checkpoint inhibition (ICI) for triple-negative breast cancer (TNBC) has been recognized recently as being independent of the degree of programmed death ligand-1 (PD-L1) positivity of infiltrating immune cells, especially for patients with axillary lymph node metastasis (ALNM). METHODS: TNBC patients with ALNM were treated surgically between 2002 and 2016 in our facility (n = 109), of whom 38 received PST before resection. The presence of tumor-infiltrating lymphocytes (TILs) expressing CD3, CD8, CD68, PD-L1 (detected by antibody SP142) and FOXP3 at primary and metastatic LN sites was quantified. RESULTS: The size of invasive tumor and the number of metastatic axillary LN were confirmed as prognostic markers. The numbers of both CD8+ and FOXP3+ TILs at primary sites were also recognized as prognostic markers, especially for overall survival (OS) (CD8, p = 0.026; FOXP3, p < 0.001). The presence of CD8+, FOXP3+ and PD-L1+ cells was better maintained in LN after PST and may contribute to improved antitumor immunity. Provided they were present as clusters of ≥ 70 positive cells, even < 1% of immune cells expressing PD-L1 at primary sites predicted a more favorable prognosis for both disease-free survival (DFS) (p = 0.004) and OS (p = 0.020). This was the case not only for 30 matched surgical patients, but also in all 71 surgical only patients (DFS: p < 0.001 and OS: p = 0.002). CONCLUSIONS: PD-L1+ , CD8+ or FOXP3+ immune cells in the tumor microenvironment (TME) at both primary and metastatic sites are significant on prognosis, which could be a clue to expect the potential for better responses to the combination of chemotherapy and ICI, especially for patients with ALNM.

Significance of prostate/pancreatic/skin cancer family history for detecting BRCA2 pathogenic variant careers among patients with breast cancer.

BACKGROUND: When considering BRCA1/2 genetic testing for diagnosis of hereditary breast and ovarian cancer (HBOC), family history (FH) of breast and ovarian cancer is commonly considered. However, FH of other HBOC-related cancers, such as prostate, pancreatic, and skin cancer (malignant melanoma), is often overlooked. METHODS: Among 945 patients who received genetic testing of BRCA1/2 at our hospital between October 2010 and September 2021, we compared the FH of 123 patients diagnosed with HBOC and 669 other patients who had breast cancer and had a documented FH. This study focused on the FH of HBOC-related cancers such as breast, ovarian, prostate, pancreatic, and skin cancer, as well as colorectal, gastric, liver, lung, and uterine cancers, which are common among Japanese, and other cancers. RESULTS: FH of prostate, pancreatic, and skin cancer was significantly higher in the BRCA2 pathogenic variant (PV) cases than in the wild-type (WT) cases. The mean number of family members are as follows: BRCA1 PV/ BRCA2 PV/ WT; prostate cancer: 0.05/ 0.34/ 0.09 (P < 0.0001, Kruskal-Wallis multiple comparisons test), pancreatic cancer: 0.13/ 0.21/ 0.10 (P = 0.01637), and skin cancer: 0.03/ 0.07/ 0.01 (P = 0.00129), respectively. CONCLUSIONS: When considering BRCA1/2 genetic testing, FH of prostate, pancreatic, and skin cancers may also be examined as HBOC-related cancers to provide testing for patients who would benefit from it. However, further studies for the association between skin cancer and HBOC will be required because it has not been reported in Japan.

Effect of renal function on neutrophil decreases following eribulin administration.

BACKGROUND: Eribulin therapy has recently attracted attention from various viewpoints, including quality of life, and is considered a standard therapy for inoperable or recurrent breast cancer. Although a reduction in renal function reportedly decreases total eribulin clearance, its association with dose-limiting toxicity and the reduction of neutrophils remain unclear. AIM: This study was aimed at analyzing the association between decreased renal function prior to eribulin administration and the occurrence of neutrophil reduction and time to treatment failure in patients with breast cancer. METHODS AND RESULTS: We retrospectively assessed patients with breast cancer, who underwent eribulin therapy between July 2011 and March 2018. Multivariate analysis revealed creatinine clearance <70 mL/min and serum albumin levels <3.9 mg/dL as predictive factors for neutrophil reduction. Even on increasing the relative dose intensity by these factors, no difference in time to treatment failure was observed, suggesting that treatment efficacy is potentially unaffected. CONCLUSIONS: For continuous eribulin therapy, eribulin may need to be administered to individual patients in accordance with renal function and albumin levels before treatment initiation.

Associations in tumor infiltrating lymphocytes between clinicopathological factors and clinical outcomes in estrogen receptor-positive/human epidermal growth factor receptor type 2 negative breast cancer.

The value of assessing tumor infiltrating lymphocytes (TILs) in estrogen receptor (ER) positive/human epidermal growth factor receptor type 2 (HER2) negative breast cancer has yet to be determined. In the present study, a total of 184 cases with early distant recurrence detected within 5 years following the primary operation, 134 with late distant recurrence diagnosed following 5 years or longer and 321 controls without recurrence for >10 years following starting the initial treatment for ER-positive/HER2 negative breast cancer, registered in 9 institutions, were analyzed. The distributions of TILs and their clinical relevance were investigated. TIL distributions did not differ significantly among the early, late and no recurrence groups, employing a 30% cut-off point as a dichotomous variable. In those who had received adjuvant chemotherapy as well as endocrine therapy, a trend toward higher TIL proportions was detected when the early recurrence group was compared with the no recurrence group employing the 30% cut-off point (P=0.064). The TIL distributions were significantly associated with nodal metastasis (P=0.004), ER status (P=0.045), progesterone receptor (PgR) status (P=0.002), tumor grade (P=0.021), and the Ki67 labeling index (LI) (P=0.002) in the no recurrence group and with the Ki67 LI in the recurrence groups (P=0.002 in early recurrence group, P=0.023 in late recurrence group). High TIL distributions also predicted shorter survival time following the detection of recurrence (P=0.026). However, these prognostic interactions were not significant in multivariate analysis (P=0.200). The present retrospective study demonstrated no significant interaction between TIL proportions and the timing of recurrence. However, higher TIL proportions were observed in breast cancer patients with aggressive biological phenotypes, which tended to be more responsive to chemotherapy. The clinical relevance of stromal TILs for identifying patients who would likely benefit from additional therapies merits further investigation in a larger patient population.

The therapeutic candidate for immune checkpoint inhibitors elucidated by the status of tumor-infiltrating lymphocytes (TILs) and programmed death ligand 1 (PD-L1) expression in triple negative breast cancer (TNBC).

BACKGROUND: The status of tumor-infiltrating lymphocytes (TILs) is a prognostic factor for triple negative breast cancer (TNBC). Recent studies have shown that programmed cell death 1 (PD-1) or programmed death ligand 1 (PD-L1) is expressed on T lymphocytes or tumor cells modulating antitumor immunity. The regulation of immune checkpoints between tumor cells and T lymphocytes may serve as a target for improvement of TNBC prognosis. We investigated TILs and PD-L1 status in TNBCs before or after preoperative systemic therapy (PST) to elucidate the clinical significance of PD-L1 expression. METHODS: Ninety patients received PST, and materials of core needle biopsies (CNB) taken before PST were available for 32 patients. TILs were scored as "% stromal", and tumors were defined as High-TILs (≥30%) or Low-TILs (<30%). The expression of PD-L1 was assessed by immunohistochemistry. RESULTS: TILs status in CNB is significant in pathological therapeutic grade: 1 vs. 2 or 3 (p = 0.0359). Disease-free survival (DFS) in patients with Low-TIL tumors were significantly worse than those with High-TIL tumors (p = 0.0383), but overall survival (OS) showed no significance (p = 0.0772). However, in patients with Low-TIL tumors, both DFS and OS in patients with High-PD-L1 expression were extremely unfavorable than in patients with Low-PD-L1 expression (p = 0.0032, p = 0.0002). CONCLUSION: The patients with TNBCs with combined Low-TILs and High-PD-L1 status in pre-PST situation showed unfavorable prognosis. The subset of TNBCs with Low-TILs and High-PD-L1 status could be the therapeutic target for immune checkpoint inhibitor.

Post-relapse survival in patients with the early and late distant recurrence in estrogen receptor-positive HER2-negative breast cancer.

BACKGROUND: Few studies have been performed on post-relapse survival in patients with the early and late distant recurrence in estrogen receptor (ER)-positive, HER2-negative breast cancer. METHODS: A total of 205 patients with the early distant recurrence and 134 patients with the late distant recurrence of ER-positive, HER2-negative breast cancer who had undergone breast surgery or neoadjuvant chemotherapy between January 2000 and December 2004 were registered from nine institutions. Prognostic factors for post-relapse survival in patients with the early and late recurrence were analyzed. RESULTS: Post-relapse survival was significantly longer in patients with the late recurrence than in patients with the early recurrence. Predictive factors for post-relapse survival in patients with the early recurrence were lack of adjuvant chemotherapy, a long disease-free interval, and long durations of endocrine therapies and chemotherapies after relapse. In patients with the late recurrence, post-relapse survival was significantly improved for those individuals with one metastatic organ at relapse and individuals who were treated with the first-line and subsequent endocrine therapies for prolonged periods. Moreover, ER expression in primary breast tumors of late recurrence patients was significantly higher with a duration of the first-line endocrine therapy >6 months than in those with a duration ≤6 months. CONCLUSION: Predictors for prognosis after relapse differed between patients with the early and late distant recurrence. Endocrine responsiveness after relapse is a key factor for improved post-relapse survival, and it is thus important to establish whether metastatic tumors are endocrine-resistant in ER-positive, HER2-negative recurrent breast cancer.

Differences in expression of the cancer stem cell marker aldehyde dehydrogenase 1 among estrogen receptor-positive/human epidermal growth factor receptor type 2-negative breast cancer cases with early, late, and no recurrence.

BACKGROUND: The significance of the expression of aldehyde dehydrogenase 1 (ALDH1), a cancer stem cell marker, for predicting the recurrence of estrogen receptor (ER)-positive/human epidermal growth factor receptor type 2 (HER2)-negative breast cancer is still poorly understood. The value of ALDH1 in predicting the time of recurrence remains unknown. METHODS: In total, 184 patients with early distant recurrence, 134 patients with late distant recurrence, and 321 control patients without recurrence for more than 10 years after starting initial treatment for ER-positive/HER2-negative breast cancer, registered in 9 institutions, were analyzed. We assessed relationships between ALDH1 and other clinicopathological features, and ALDH1 expression was compared among the three groups. The relationship between ALDH1 expression and overall survival after recurrence was also evaluated in each group. RESULTS: The rates of ALDH1 expression positivity (more than 1 %) in the early, late, and no recurrence groups were 18.4 %, 13.4 %, and 8.4 %, respectively. ALDH1 expression correlated significantly with lymph node metastases (p = 0.048) and the Ki-67 labeling index (p < 0.001) in the early recurrence group. Multivariate analysis revealed ALDH1 expression to be significantly higher in the early recurrence group than in the no recurrence group (adjusted OR 2.140, 95 % CI 1.144-4.003, p = 0.016). Moreover, there was a significant difference in ALDH1 expression between the early and no recurrence groups receiving adjuvant endocrine therapy and chemotherapy (adjusted OR 4.625, 95 % CI 1.881-12.474, p < 0.001). However, there was no difference in ALDH1 expression between the late and no recurrence groups in univariate analysis (OR 1.507, 95 % CI 0.738-2.998, p = 0.253). In multivariate analysis, ALDH1 was not a factor independently predicting overall survival after the detection of recurrence (adjusted OR 1.451, 95 % CI 0.985-2.085, p = 0.059). CONCLUSIONS: Among patients with ER-positive/HER2-negative breast cancer, ALDH1 expression was more common in those with early recurrence, and this expression was found to be associated with a more aggressive breast cancer phenotype than that in the patients without recurrence. Further study is needed to clarify the prognostic significance of the heterogeneity of cancer stem cells and to confirm their role in resistance to chemotherapy.

[Safety and Tolerance of Dose-Dense Epirubicin and Cyclophosphamide (EC) with Pegfilgrastim for Japanese Patients with Early Breast Cancer].

With the approval of pegfilgrastim, the use of dose-dense epirubicin and cyclophosphamide (EC) for breast cancer has become acceptable in Japan. Thus, we aimed to evaluate its safety and tolerability in Japanese patients. Nine breast cancer patients with a high risk of preoperative or postoperative recurrence received EC therapy(epirubicin 90 mg/m(2) and cyclo- phosphamide 600 mg/m(2))for 4 cycles every 2 weeks in combination with a subcutaneous injection of pegfilgrastim (3.6 mg) on day 2 of each cycle. Treatment was discontinued in 1 and extended in 1 of the 9 patients, and the mean relative dose intensity(RDI)was good at 0.93. No serious adverse events were observed, indicating good tolerability. The regimen has potential for use in cases in which the treatment dose needs to be increased. grade 4 neutropenia was observed in all the 9 patients on day 8, with 6 patients developing febrile neutropenia. In Japan, data on changes in neutrophil count associated with pegfilgrastim administration under anthracycline-based chemotherapy are currently insufficient, and further study is required.

Clinicopathological factors predicting early and late distant recurrence in estrogen receptor-positive, HER2-negative breast cancer.

BACKGROUND: Most studies analyzing prognostic factors for late relapse have been performed in postmenopausal women who received tamoxifen or aromatase inhibitors as adjuvant endocrine therapy for estrogen receptor (ER)-positive breast cancer. METHODS: A total of 223 patients (108 premenopausal and 115 postmenopausal) with early distant recurrence and 149 patients (62 premenopausal and 87 postmenopausal) with late distant recurrence of ER-positive, HER2-negative breast cancer who were given their initial treatment between 2000 and 2004 were registered from nine institutions. For each late recurrence patient, approximately two matched control patients without relapse for more than 10 years were selected. Clinicopathological factors and adjuvant therapies were compared among the three groups by menopausal status and age. RESULTS: Factors predicting early recurrence in premenopausal women were large tumor size, high lymph node category and high tumor grade, whereas predictors for late recurrence were large tumor size and high lymph node category. In postmenopausal women under 60 years of age, factors predicting early recurrence were bilateral breast cancer, large tumor size, high lymph node category, low PgR expression and high Ki67 labeling index (LI), while predictors for late recurrence were large tumor size and high lymph node category. On the other hand, in postmenopausal women aged 60 years or older, factors predicting early recurrence were bilateral breast cancer, large tumor size, high lymph node category, high tumor grade, low ER expression and high Ki67 LI, whereas predictors for late recurrence were high lymph node category, low ER expression and short duration of adjuvant endocrine therapy. CONCLUSION: Predictors of early and late distant recurrence might differ according to menopausal status and age.

Array comparative genomic hybridization analysis revealed four genomic prognostic biomarkers for primary gastric cancers.

Unlike the case with some other solid tumors, whole genome array screening has not revealed prognostic genetic aberrations in primary gastric cancer. Comparative genomic hybridization (CGH) using bacterial artificial chromosome (BAC) arrays for 56 primary gastric cancers resulted in identification of four prognostic loci in this study: 6q21 (harboring FOXO3A; previously FKHRL1), 9q32 (UGCG), 17q21.1 approximately q21.2 (CASC3), and 17q21.32 (HOXB3 through HOXB9). If any one of these four loci was deleted, the prognosis of the patient was significantly worse (P = 0.0019). This was true even for advanced tumors (stage IIIA, IIB, or IV, n = 39) (P = 0.0113), whereas only 1 of the 17 patients with less advanced tumors (stage IA, IB, or II; n = 17) died of disease after surgery. Multivariate analysis according to the status of four BACs or pathological stage based on the Japanese Classification of Gastric Carcinoma (stages IA, IB, and II vs. stages IIIA, IIIB, and IV) demonstrated that the BAC clone status was also an independent prognostic factor (P = 0.006). These findings may help predict which patients with malignant potential need more intensive therapy, or may point to new therapeutic approaches especially for advanced tumors. The parameter here termed the integrated genomic prognostic biomarker may therefore be of clinical utility as a prognostic biomarker.

Biology of neuroblastomas that were found by mass screening at 6 months of age in Japan.

BACKGROUND: Mass screening (MS) of neuroblastoma has been carried out by measuring the urinary catecholamine metabolites in infants at the age of 6 months in Japan. We assessed the incidence of neuroblastoma that may be a target for MS by studying tumor biology. PROCEDURE: FISH on chromosome 1 and MYCN analysis was performed on 453 patients that were classified into three clinical groups (287 infants found by MS, 51 infants < 12 months diagnosed clinically, and 115 children >or=12 months diagnosed clinically). The relationship between the biological types of tumors and the clinical outcome was examined. RESULTS: Type 1 (trisomy 1 and normal MYCN), type 2 (disomy 1/tetrasomy 1 and normal MYCN), and type 3 (disomy 1/tetrasomy 1 and amplified MYCN) tumors were found in 88.2%, 10.5%, and 1.4% of infants found by MS, in 68.0%, 24.0%, and 8.0% of infants diagnosed clinically, and in 23.4%, 42.3%, and 34.2% of children diagnosed clinically (P < 0.001). Infants with type 1 tumors found by MS or diagnosed clinically had earlier stages of the disease (P < 0.0001 and P = 0.0005) and better overall survival (P < 0.001 and P = 0.005) than children with type 1 tumors diagnosed clinically. Infants with type 2 tumors found by MS, had earlier stages (P = 0.06 and P < 0.0001) and better overall survival (P = 0.014 and P < 0.001) than infants or children with type 2 tumors diagnosed clinically. All three clinical groups of patients with type 3 tumors had advanced stages and dismal prognoses. CONCLUSIONS: About 12% of tumors found by MS showed unfavorable biological (types 2 and 3) characteristics.

Chromosomes that show partial loss or gain in near-diploid tumors coincide with chromosomes that show whole loss or gain in near-triploid tumors: evidence suggesting the involvement of the same genes in the tumorigenesis of high- and low-risk neuroblastomas.

We performed two-color fluorescence in situ hybridization analysis to detect the numbers of chromosomes 1 and 17, 1p deletion, and 17q gain in 177 neuroblastomas, including 101 tumors that were found by a mass-screening program for infants. Sixty-eight tumors with disomy 1 or tetrasomy 1 were classified as the Dis1 group, and 109 tumors with trisomy 1, pentasomy 1, or a mixed population of cells with trisomy 1 and cells with tetrasomy 1 were classified as the Tris1 group. 17q gain was the most frequent genetic event, followed by 1p deletion, and MYCN amplification in both Dis1 and Tris1 tumors. However, the incidence of all the genetic events was higher in Dis1 tumors than in Tris1 tumors. These findings suggest that Tris1 tumors are more resistant to acquiring the genetic events than are Dis1 tumors. In addition, there was an accumulation of genetic events in more advanced stages, with the exception of a high incidence of 17q gain in the stage IVS Tris1 tumors. Comparative genomic hybridization analysis, which was performed in 59 of the 177 tumors, showed that chromosomes partially lost or gained in Dis1 tumors coincided with chromosomes totally lost or gained in Tris1 tumors. Dis1 and Tris1 tumors were considered to have near-diploid/tetraploid and near-triploid/pentaploid chromosome numbers, respectively. These findings suggest that the same tumor-suppressor genes or oncogenes may be involved in the development and progression of both high- and low-risk neuroblastomas, and that the ploidy state of the tumor plays a fundamental role in the heterogeneous behavior.