Rhabdomyosarcoma in Adults: De Novo or Conversion From Non-seminomas?

Rhabdomyosarcoma (RMS) is a highly sporadic, very aggressive, and fatal soft tissue tumor in adults. Although more common and treatable in the pediatric population, the occurrence of pleomorphic RMS in adults has a low incidence. Hence, it is not easy to treat. Surgery is the primary definitive treatment, along with radiation therapy, while adjuvant chemotherapy has recently gained popularity. We present an infrequent case of RMS in a patient with a recent history of mixed non-seminomatous germ-cell tumor testicular cancer. Therefore, it was challenging to treat the RMS as a new malignancy or as a recurrence of non-seminomatous testicular cancer. Our patient passed away, unfortunately, but we hope this case can help the minimal data in this regard in order to save more lives in the future.

A Case Report on Alpha-Fetoprotein-Positive Colorectal Cancer

Alpha-fetoprotein (AFP) is commonly produced by hepatocellular carcinoma and yolk sac tumors, while AFP in colorectal cancer (CRC) is a rare association. We report a case of a patient with primary AFP-producing CRC, which was successfully treated with surgery and adjuvant chemotherapy. This case highlighted the importance of recognizing a case of AFP-producing CRC.  This case report discussed a 59-year-old male who had a history of hepatitis B infection, with two months of intermittent fresh per rectal bleeding. Given his previous burden of hepatitis B infection, and the serum AFP level on admission was high (212.6 ng/mL), this raised suspicions of possible hepatocellular carcinoma. Therefore, a triphasic computed tomography of the liver was performed, which revealed an incidental hepatic flexure lesion with no involvement of the liver. Subsequent colonoscopy revealed a large friable tumor obstructing the whole lumen of the proximal transverse colon. He then underwent an emergency extended right hemicolectomy. Histopathological examination showed a Duke C mucinous adenocarcinoma (T3N2b), with a satisfactory resected margin. Immunohistochemical analysis indicated that the tumor exhibited positivity for MLH1/MSH2/MSH6/PMS2 (+++) and human epidermal growth factor receptor 2 (HER2), and notably, it also stained positive for AFP. The postoperative period was uneventful, and serum AFP level eventually normalized. The patient completed eight cycles (four months) of adjuvant chemotherapy with capecitabine and oxaliplatin (CAPOX) regimen. A follow-up CT scan and colonoscopy showed no evidence of local or distant recurrence after 12 months of surveillance. AFP may be useful for not only hepatocellular carcinoma but also CRC. In particular, this case report has fully demonstrated the unexpected incidence and emphasized the importance of early recognition and appropriate treatment to prevent potential oversights in the diagnosis of CRC.

Cutoff values of protein induced by vitamin K absence or antagonist II for diagnosing hepatocellular carcinoma

Protein induced by vitamin K absence or antagonist II (PIVKA-II) is a promising serum marker for hepatocellular carcinoma (HCC). There are limited data on its cutoff value in HCC for Taiwanese cirrhosis patients. This study aimed to investigate the diagnostic value of PIVKA-II levels in patients with suspected HCC. In total, 88 patients with chronic hepatitis and suspected HCC by ultrasound, elevated α-fetoprotein (AFP) or PIVKA-II levels were consecutively enrolled. Their baseline characteristics and findings on dynamic phases of computed tomography (CT) or magnetic resonance imaging (MRI) were examined. Sixty participants had cirrhosis and 34 had HCC. The median levels of PIVKA-II in non-cirrhosis and cirrhosis patients without or with HCC were 28.0, 48.0, and 847.0 mAU/mL, respectively. The optimal cutoff value of PIVKA-II in predicting HCC was 78.0 mAU/mL. Combining AFP with PIVKAII mildly increased its diagnostic performance for HCC, yielding higher specificity and positive predictive value. Significant factors predicting HCC in multivariate regression analysis were PIVKA >78.0 mAU/mL and fatty liver. Monitoring PIVKA-II level is suitable for noninvasively assessing HCC in patients with chronic hepatitis, particularly with AFP.

Assessment of Maternal Serum Biochemical Attributes and Fetal Ultrasound Scans in First-Trimester Low-Risk Noninvasive Prenatal-Tested Pregnant Women

INTRODUCTION

The first trimester of pregnancy is marked by several important disrupting changes as a result of complex biological upshot of events required for the development of the fetus. These changes in the biological events result in changes in the maternal serum biomarkers that are associated with fetal growth. The aim of the present study was to evaluate the correlation between the maternal blood biochemical determinants such as pregnancy-associated plasma protein-A (PAPP-A) and alpha fetoprotein (AFP) with ultrasound scans during early pregnancy in the first trimester.

METHODS

The study included 139 women whose fetus was alive between 11±1 weeks of gestation. The risk of fetal chromosomal abnormalities at first trimester was analyzed by the VeriSeq NIPT Solution v2 platform (Illumina, San Diego, CA, USA) for noninvasive prenatal testing (NIPT) assay. The PAPP-A and AFP levels were evaluated by chemiluminescent immunoassays. The levels of PAPP-A and AFP were correlated with the fetal heart rate (HR), crown rump length (CRL), and nuchal translucency (NT) by Pearson's correlation analysis.

RESULTS

The mean age of the participants was 28.35±3.87 years (minimum=21, maximum=35). The mean AFP and PAPP-A levels in the maternal plasma were 14.76±1.04 ng/mL and 4.37±0.86 mIU/ml respectively. The mean FHR, CRL, and NT were 138±7.62 bpm, 59±3.24 mm, and 2.3±0.61 mm respectively. PAPP-A and AFP significantly (p<0.05) correlated with fetal HR, CRL, and NT at 11±1 weeks of gestation. The mean ratio of AFP:PAPP-A in low-risk pregnancies was 3.37.

CONCLUSIONS

The maternal serum biochemical attributes correlated well with the fetal ultrasound scans. The findings of the present study can prove to be clinically useful for clinical research, obstetrics, and gynaecology, especially for examinations of first-trimester pregnancies.

Misleading Germ Cell Phenotype in Pulmonary NUT Carcinoma Harboring the ZNF532-NUTM1 Fusion

NUT carcinoma (aka NUT midline carcinoma) is a rare, still significantly underrecognized aggressive malignancy. Although historically considered a midline malignancy of children and young adults, NUT carcinoma can originate in almost any body site and in any age group. Beside the classic BRD4-NUTM1 fusion, less common fusion partners include BRD3, NSD3, ZNF532, and ZNF592. Other fusions, including CIC, MGA, MXD4, MXD1, and BCORL1 are associated with sarcomas or cancers of unknown histogenesis. Involvement of the Z4 zinc finger protein (ZNF) family members ZNF532 and ZNF592 is exceedingly rare with only 3 recently reported cases. We herein describe a ZNF532-NUTM1-rearranged NUT carcinoma presenting as a 7.5 cm mass in the left lower lung lobe of a 65-year-old woman. Histology revealed undifferentiated monotonous small round cells with focal epithelioid and rhabdoid elements within a variably myxoid stroma. Immunohistochemistry revealed paucity of keratins and variable p63 combined with extensive CD30 and PLAP expression, leading to initial diagnoses of combined small cell carcinoma, CD30-positive unclassified hematolymphoid malignancy and malignant germ cell neoplasm. Negativity for other more specific germ cell markers justified seeking a fourth opinion, which revealed diffuse expression of the NUT antibody. The diagnosis was then confirmed by fluorescence in situ hybridization. Targeted RNA sequencing revealed the ZNF532-NUTM1 fusion. Screening of 7 NUT carcinomas (5 with BRD4-NUTM1 and 2 with NSD3-NUTM1 fusions) for germ cell markers revealed focal SALL4 reactivity in 3 cases (combined with variable AFP expression in 2), but none expressed CD30 or PLAP. An aberrant germ cell immunophenotype should be considered in NUT carcinoma to avoid misinterpretation as genuine germ cell malignancy as both diseases predominantly affect the young population, frequently involve the mediastinum and can be associated with elevated serum AFP.

BALAD and BALAD-2 predict survival of hepatocellular carcinoma patients: a North American cohort study

BACKGROUND

The BALAD score and BALAD-2 class derived from bilirubin, albumin, AFP, AFP-L3, and des-gamma-carboxyprothrombin (DCP) are effective in predicting mortality in HCC, but have not been validated in North America.

METHODS

148 HCC patients from 2000 to 2015 who had all five biomarkers tested at diagnosis were included. Hazard ratios (HR) were calculated.

RESULTS

75 patients died during a median follow-up of 21.9 months. 1-and 3-year survival rates were 70.8% and 47.6%. 114 (77%) had cirrhosis. The HR (95%CI) for death were 1.24 (0.42-3.67), 1.79 (0.61-5.26), 2.83 (0.95-8.38), and 7.19 (2.26-22.91) for BALAD scores 1, 2, 3, and 4 vs. BALAD 0. The HR (95%CI) for death were 1.25 (0.65-2.40), 1.75 (0.94-3.23), and 6.20 (3.29-11.68) for BALAD-2 classes 2, 3, and 4 vs. BALAD-2 class 1. A multivariate model incorporating maximal tumor diameter, tumor number, neutrophil-lymphocyte ratio, and BALAD had HR of 1.43 (1.14-1.81) per increase of 1 BALAD score. A similar model with BALAD-2 had HR of 1.50 (1.18-1.90) per increase of 1 BALAD-2 class.

CONCLUSION

BALAD models at diagnosis can predict the survival of HCC patients in North America. AFP, AFP-L3, and DCP reflect tumor progression and metastasis of HCC and distinguish the BALAD model from other predictive models.

PIVKA-II is a useful tool for diagnostic characterization of ultrasound-detected liver nodules in cirrhotic patients

Protein induced by vitamin K absence-II (PIVKA-II) is a potential screening marker for hepatocellular carcinoma (HCC). Limited data are available about its utility in discriminating neoplastic from regenerative nodules at ultrasonography (US) evaluation in cirrhotic patients. Aim of this study was to investigate the diagnostic utility of PIVKA-II in cases showing liver nodules of uncertain diagnosis at US.Ninety cirrhotics with US evidence of liver nodule(s) were enrolled. All patients underwent blood sampling within 1 week of US and were thereafter followed up. HCC was confirmed in 40/90 cases, and in all cases it was in a very early/early stage. All sera were tested for PIVKA-II and alpha-fetoprotein (AFP) at the end of follow-up. PIVKA-II at a cut off of 60 mAU/mL was significantly associated with HCC at both univariate and multivariate analysis (P = .016 and P = .032, respectively). AFP at a cut off of 6.5 ng/mL was not associated with HCC at univariate analysis (P = .246). ROC curves showed that PIVKA-II had 60% sensitivity, 88% specificity, 80% positive predictive value (PPV), and 73% negative predictive value (NPV), whereas AFP had 67% sensitivity, 68% specificity, 63% PPV, and 72% NPV. AUROC curves showed that the combination of both biomarkers increased the diagnostic accuracy for HCC (AUC 0.76; sensitivity 70%, specificity 94%, PPV 91%, and NPV 79%).In conclusion, PIVKA-II is a useful tool for the diagnostic definition of US-detected liver nodules in cirrhotic patients, and it provides high diagnostic accuracy for HCC when combined with AFP.

Usefulness of AFP, AFP-L3, and PIVKA-II, and their combinations in diagnosing hepatocellular carcinoma

Alpha-fetoprotein (AFP), Lens culinaris-agglutinin-reactive fraction of AFP (AFP-L3), and protein induced by vitamin K absence or antagonist-II (PIVKA-II) are widely used as tumor markers for the diagnosis of hepatocellular carcinoma (HCC). This study compared the diagnostic values of AFP, AFP-L3, and PIVKA-II individually and in combination to find the best biomarker or biomarker panel.Seventy-nine patients with newly diagnosed HCC and 77 non-HCC control patients with liver cirrhosis were enrolled. AFP, AFP-L3, and PIVKA-II were measured in the same serum samples using microchip capillary electrophoresis and a liquid-phase binding assay on an automatic analyzer. Receiver-operating characteristic curve analyses were also applied to all combinations of the markers.When the 3 biomarkers were analyzed individually, AFP showed the largest area under the receiver-operating characteristic curve (AUC) (0.751). For combinations of the biomarkers, the AUC was highest (0.765) for "PIVKA-II > 40 mAU/mL and AFP > 10 ng/mL." The combination of "PIVKA-II > 40 mAU/mL and AFP > 10 ng/mL and AFP-L3 > 10%" had worse sensitivity and lower AUC (P = 0.001). The highest AUC of a single biomarker was highest for AFP and of a combination was "PIVKA-II > 40 mAU/mL and AFP > 10 ng/mL," with this also being the case when the cut-off value of AFP and AFP-L3 was changed.Alpha-fetoprotein showed the best diagnostic performance as a single biomarker for HCC. The diagnostic value of AFP was improved by combining it with PIVKA-II, but adding AFP-L3 did not contribute to the ability to distinguish between HCC and non-HCC liver cirrhosis. These findings were not altered when the cut-off value of AFP and AFP-L3 was changed.

Biomarker-based prognosis in hepatocellular carcinoma: validation and extension of the BALAD model

BACKGROUND

The Japanese 'BALAD' model offers the first objective, biomarker-based, tool for assessment of prognosis in hepatocellular carcinoma, but relies on dichotomisation of the constituent data, has not been externally validated, and cannot be applied to the individual patients.

METHODS

In this Japanese/UK collaboration, we replicated the original BALAD model on a UK cohort and then built a new model, BALAD-2, on the original raw Japanese data using variables in their continuous form. Regression analyses using flexible parametric models with fractional polynomials enabled fitting of appropriate baseline hazard functions and functional form of covariates. The resulting models were validated in the respective cohorts to measure the predictive performance.

RESULTS

The key prognostic features were confirmed to be Bilirubin and Albumin together with the serological cancer biomarkers, AFP-L3, AFP, and DCP. With appropriate recalibration, the model offered clinically relevant discrimination of prognosis in both the Japanese and UK data sets and accurately predicted patient-level survival.

CONCLUSIONS

The original BALAD model has been validated in an international setting. The refined BALAD-2 model permits estimation of patient-level survival in UK and Japanese cohorts.

LARP1 predict the prognosis for early-stage and AFP-normal hepatocellular carcinoma

BACKGROUND

The La-related protein 1 (LARP1) has been found to be a RNA binding protein and was related to spermatogenesis, embryogenesis and cell-cycle progression. The aim of this study was to investigate the prognostic value of LARP1 in hepatocellular carcinoma (HCC).

METHODS

LARP1 expression was examined in 15 HCC cell lines and 272 clinical specimens using real-time PCR, immunohistochemistry (IHC) and western blot analysis (WB). LARP1 expression was also studied in 6 paired HCC lesions and the adjacent non-cancerous tissue samples. Statistical analyses were applied to derive association between LARP1 expression scores and clinical characters as well as patient survival.

RESULTS

mRNA and protein levels of LARP1 were higher in HCC cell lines and HCC lesions than in normal liver epithelial cells and the paired adjacent noncancerous tissues. LARP1 expression was correlated to survival time, vital status, tumor size and Child-Pugh score. Overall survival analysis showed HCC patients with high LARP1 expression level had lower survival rate (P<0.01). Importantly, this correlation remained significant in patients with early-stage HCC or with normal serum AFP level.

CONCLUSIONS

LARP1 protein may represent a promising biomarker for predicting the prognosis of HCC, including in early-stage and AFP-normal patients.

Increased alpha-fetoprotein receptor in the serum of patients with early-stage breast cancer

The alpha-fetoprotein (afp) receptor (recaf) is an oncofetal antigen found in most types of cancer. Using a competitive radioimmunoassay, we measured the concentration of serum recaf in three sets of samples.Set 1 was blind and consisted of 119 normal subjects, 43 breast cancer patients (stages i and ii), and 20 patients with benign breast conditions. In this set, the assay discriminated normal from cancer samples with a receiver operating characteristic for the area under the curve (ROC(AUC)) of 0.983; with 95% specificity and 93% sensitivity at a cut-off of 4.6 K (arbitrary) recaf units; and with 72% sensitivity and 100% specificity at a cut-off of 7.3 K units. At 7.3 K units, the specificity for benign breast conditions was 85%, and the sensitivity was 72% (ROC(AUC) was 0.773). Carcinoembryonic antigen and cancer antigen 15-3 respectively showed 39% and 41% sensitivity, with 95% specificity in comparisons of normal with cancer samples, and 34% and 44% sensitivity, with 85% specificity in comparisons of benign with cancer samples. Set 2 consisted of 353 normal, 30 benign, and 64 cancer samples (stages ii and iii). The recaf assay sensitivity in discriminating normal from cancer samples was 97%, with 97% specificity. Benign compared with cancer samples showed 87% sensitivity, with 97% specificity. Set 3 included only 40 normal and 40 cancer samples. The assay sensitivity was 89%, with 100% specificity. Sets 2 and 3 were not tested with carcinoembryonic antigen and cancer antigen 15-3.These results strongly suggest that the recaf assay could be used for detecting breast cancer in its early stages.

Transforming growth factor-beta signaling promotes hepatocarcinogenesis induced by p53 loss

Hepatocellular carcinoma (HCC) results from the accumulation of deregulated tumor suppressor genes and/or oncogenes in hepatocytes. Inactivation of TP53 and inhibition of transforming growth factor-beta (TGF-β) signaling are among the most common molecular events in human liver cancers. Thus, we assessed whether inactivation of TGF-β signaling, by deletion of the TGF-β receptor, type II (Tgfbr2), cooperates with Trp53 loss to drive HCC formation. Albumin-cre transgenic mice were crossed with floxed Trp53 and/or floxed Tgfbr2 mice to generate mice lacking p53 and/or Tgfbr2 in the liver. Deletion of Trp53 alone (Trp53(KO) ) resulted in liver tumors in approximately 41% of mice by 10 months of age, whereas inactivation of Tgfbr2 alone (Tgfbr2(KO) ) did not induce liver tumors. Surprisingly, deletion of Tgfbr2 in the setting of p53 loss (Trp53(KO) ;Tgfbr2(KO) ) decreased the frequency of mice with liver tumors to around 17% and delayed the age of tumor onset. Interestingly, Trp53(KO) and Trp53(KO) ;Tgfbr2(KO) mice develop both HCC and cholangiocarcinomas, suggesting that loss of p53, independent of TGF-β, may affect liver tumor formation through effects on a common liver stem cell population. Assessment of potential mechanisms through which TGF-β signaling may promote liver tumor formation in the setting of p53 loss revealed a subset of Trp53(KO) tumors that express increased levels of alpha-fetoprotein. Furthermore, tumors from Trp53(KO) mice express increased TGF-β1 levels compared with tumors from Trp53(KO) ;Tgfbr2(KO) mice. Increased phosphorylated Smad3 and ERK1/2 expression was also detected in the tumors from Trp53(KO) mice and correlated with increased expression of the TGF-β responsive genes, Pai1 and Ctgf.

CONCLUSION

TGF-β signaling paradoxically promotes the formation of liver tumors that arise in the setting of p53 inactivation.

Use of surveillance for hepatocellular carcinoma among patients with cirrhosis in the United States

Surveillance for hepatocellular carcinoma (HCC) in patients with cirrhosis is recommended but may not be performed. The extent and determinants of HCC surveillance are unknown. We conducted a population-based United States cohort study of patients over 65 years of age to examine use and determinants of prediagnosis surveillance in patients with HCC who were previously diagnosed with cirrhosis. Patients diagnosed with HCC during 1994-2002 were identified from the linked Surveillance, Epidemiology, and End-Results registry-Medicare databases. We identified alpha-fetoprotein (AFP) and ultrasound tests performed for HCC surveillance, and examined factors associated with surveillance. We identified 1,873 HCC patients with a prior diagnosis of cirrhosis. In the 3 years before HCC, 17% received regular surveillance and 38% received inconsistent surveillance. In a subset of 541 patients in whom cirrhosis was recorded for 3 or more years prior to HCC, only 29% received routine surveillance and 33% received inconsistent surveillance. Among all patients who received regular surveillance, approximately 52% received both AFP and ultrasound, 46% received AFP only, and 2% received ultrasound only. Patients receiving regular surveillance were more likely to have lived in urban areas and had higher incomes than those who did not receive surveillance. Before diagnosis, approximately 48% of patients were seen by a gastroenterologist/hepatologist or by a physician with an academic affiliation; they were approximately 4.5-fold and 2.8-fold, respectively, more likely to receive regular surveillance than those seen by a primary care physician only. Geographic variation in surveillance was observed and explained by patient and physician factors.

CONCLUSION

Less than 20% of patients with cirrhosis who developed HCC received regular surveillance. Gastroenterologists/hepatologists or physicians with an academic affiliation are more likely to perform surveillance.

Postoperative changes in protein-induced vitamin K absence or antagonist II levels after hepatectomy in patients with hepatocellular carcinoma: relationship to prognosis

BACKGROUND

alpha-Fetoprotein (AFP) has been used as a marker for hepatocellular carcinoma (HCC). However, AFP levels are often high in patients with chronic hepatitis or cirrhosis. Protein-induced vitamin K absence or antagonist II (PIVKA-II) is more sensitive for the diagnosis of HCC and prediction of patient survival. Changes in these markers after treatment may reflect treatment curability and patient outcome.

METHODS

We conducted a retrospective analysis of prognosis of 63 HCC patients with high preoperative levels of AFP and PIVKA-II who underwent hepatectomy and examined the relationship between postoperative changes in both markers at 1 month and patient survival. Subjects were divided into three groups according to changes in these tumour markers after hepatectomy: normalization (N) group, decreased but still above the normal level (D) group and unchanged (U) group.

RESULTS

There were no significant differences in the numbers of patients who developed tumour recurrence between changes in AFP and PIVKA-II. Survival analysis showed no significant differences in tumour-free and overall survivals between groups with respect to AFP level. The PIVKA-II-N group showed significantly better tumour-free and overall survival compared with the D and U groups (p<0.01). Multivariate analysis that included other prognostic factors identified changes in PIVKA-II level as a significant and independent prognostic factor associated with overall survival.

DISCUSSION

Although changes in AFP did not correlate with patient prognosis, normalization of PIVKA-II was significantly associated with good patient survival after hepatectomy. Normalization of PIVKA-II after hepatectomy reflected the efficacy of treatment and is a suitable predictor of prognosis in HCC patients.

Menstrual cycle dependent variability for serum tumor markers CEA, AFP, CA 19-9, CA 125 and CA 15-3 in healthy women

Information on menstrual cycle dependent variation of tumor markers in healthy women is a subject of diagnostic efficiency and has an impact in elucidating the normal function of these markers. In this study midfollicular and midluteal concentrations of serum CEA, AFP, CA 19-9, CA 125, CA 15-3 and their relations with LH, FSH, prolactin, estradiol and progesterone were evaluated during ovulatory cycles in a group of 23 healthy female individuals. Samples were collected on the 7th and 21st day of the same menstrual cycle. Tumor marker and hormone concentrations were determined with chemiluminescence or electrochemiluminescence EIA methods. A significant phase-dependent difference was observed for CA 15-3, midluteal concentrations (mean +/- SEM; 26.33 +/- 1.56 U/ml) higher than the midfollicular (mean +/- SEM; 19.27 +/- 1.49 U/ml) concentrations (p < 0.001). But an obvious difference for other tumor markers investigated did not exist. Significant correlations of follicular and luteal CA 125 levels with body mass index of the subjects were observed (r:0.52, p < 0.05 and r:0.57, p < 0.005, respectively). CA 15-3 antigen is a product of the MUC-1 gene which is expressed in abundance by endometrial epithelial cells in the secretory phase of the menstrual cycle which may be the potential source of variability. The association of CA 125 levels with obesity suggests a possible role of adipose tissue in CA 125 metabolism. In conclusion our data suggest that in healthy women serum CA 15-3 levels are significantly elevated in the midluteal phase of the menstrual cycle compared to midfollicular phase. Therefore, consideration of menstrual cycle dependent variability for CA 15-3 appears indicated in interpretation of individual results.

Establishment and characterization of a rat yolk sac tumor cell line, NMT-1, producing alpha-fetoprotein, with potential for lymphatic metastasis

A new cell line producing alpha-fetoprotein, designated NMT-1, was established from rat yolk sac tumor with the potential for lymphatic metastasis in inbred Wistar rats. In this paper, we investigated the characteristics of NMT-1 cells. The cell line grew in a monolayer and had a polygonal epithelioid appearance in phase-contrast microscopy. The doubling time of NMT-1 cells during exponential growth was approximately 16 h in RPMI-1640 with 10% fetal calf serum. The D0 value for radiation sensitivity was 97 +/- 3 cGy. The extrapolation number, n, for NMT-1 was 1.08 +/- 0.15. In the log phase, the G0/G1, S and G2/M fractions were 23.2%, 62.1% and 14.3%, respectively. Tumor take was observed in all of the rats inoculated with NMT-1 cells. In the case of flank tumor, the mean survival time was 104 days after inoculation with 10(6) tumor cells. Inguinal, axillary, paraaortic, mesenteric and mediastinal lymphnode metastases were observed in all rats inoculated with NMT-1 cells. Rats which survived for a long time developed metastases in a lymphatic vessels of the liver, lung and/or kidney microscopically. The biological behavior and the histopathological features of the tumor induced by inoculation with NMT-1 cells were the same as those of the original tumor induced by fetectomy.