Comparative genomic hybridization analysis of clear cell sarcoma of the kidney

BACKGROUND: Clear cell sarcoma of the kidney (CCSK) is a rare malignant pediatric tumor, distinguished from the Wilms tumor by its characteristic histologic features and a more aggressive clinical behavior with a tendency to metastasize to bone. Genetic studies on CCSK are limited and no consistent findings have been reported. PROCEDURE: We examined four cases of CCSK for presence of consistent genetic alterations using comparative genomic hybridization (CGH). This is the first report concerning CGH analysis of CCSK. RESULTS: Three of the tumors showed no chromosome gains or losses. One of the tumors had gains of 1 q and the terminal end of 11 q. CONCLUSIONS: These results are consistent with previous findings of limited chromosomal changes in CCSK karyotypes. Gain of 1 q in CCSK warrants further investigation. Copy number gains of 1 q have been repeatedly demonstrated in soft tissue and bone sarcomas, as well as other tumors, implying the presence of genes involved in tumor development and/or progression.     

Functional and Gene Expression Analysis of the p53 Signaling Pathway in Clear Cell Sarcoma of the Kidney and Congenital Mesoblastic Nephroma

Mutation of p53 has been implicated in progression of classical Wilms tumor (WT) into the anaplastic variant (AWT), drug resistance, and poor prognosis. Because of prognostic similarities, clear cell sarcoma of the kidney (CCSK) has been classified with AWT and other aggressive pediatric renal tumors, apart from congenital mesoblastic nephroma (CMN), which is instead a relatively benign tumor of neonates. Initially, CCSK and CMN were assumed to be ontologically related, but the role of p53 in the pathogenesis of either disease has not been sufficiently evaluated as in AWT. We examined the status of p53 in CMN and CCSK in comparison to AWT by immunohistochemistry and mRNA analysis of p53, the downstream effector p21 ^WAF-1/CIP-1 (p21), the multidrug resistance gene MDR-1, a putative target of p53, and the p53-antagonist Mdm-2. Surprisingly, strong p53 nuclear immunoreactivity was found in cultures from two CMN specimens, but not in frozen or fixed tumor tissue from five other CMN specimens, nor in cell lines or tumor tissue from CCSK. Sequence analysis excluded p53 mutations. The size of the p53 mRNA in CMN and CCSK primary tumors excluded gross deletions or rearrangements. Low levels of Mdm-2 mRNA in CCSK and CMN primary tumors and cultures did not support a role for Mdm-2. Absence of MDR-1 mRNA excluded MDR-1 in the drug-resistant phenotype of CCSK. Cisplatin-induced p21 transactivation assays and G₁ cell cycle arrest analyses showed that p21 transactivation and G₁ arrest occurred in both CCSK and CMN cultures, demonstrating integrity of the p53 signal transduction pathway. Absence of p53 functional abnormalities excluded relationships between CCSK and CMN as in AWT, supporting the association of cellular CMN with congenital fibrosarcomas as more recently proposed. Received November 12, 2001; accepted February 4, 2002.     

Clear cell sarcoma of kidney involving a horseshoe kidney and harboring EGFR internal tandem duplication

Clear cell sarcoma of kidney (CCSK) is a rare renal malignancy, previously unreported in horseshoe kidney (HSK). B‐cell lymphoma 6 corepressor (BCOR) gene internal tandem duplication (ITD) was identified as a recurrent somatic alteration in approximately 85% of CCSKs. This and the YWHAE–NUTM2B/E fusion, the second most common recurrent molecular alteration in CCSK (10%), are considered to be mutually exclusive. However, there is a subset of CCSKs that do not harbor either the BCOR‐ITD or YWHAE–NUTM2 translocation and lack known molecular alterations. Herein, we report the first case of CCSK arising in HSK and harboring epidermal growth factor receptor ITD.     

Results of the SIOP 93-01/GPOH trial and study for the treatment of patients with unilateral nonmetastatic Wilms Tumor

BACKGROUND: The treatment of Wilms Tumor is integrated into clinical trials since the 1970's. In contrast to the National Wilms Tumor Study Group (NWTSG) the SIOP trials and studies largely focus on the issue of preoperative therapy to facilitate surgery of a shrunken tumor and to treat metastasis as early as possible. PATIENTS AND METHODS: In the SIOP 93-01/GPOH trial and study 1 020 patients with a newly diagnosed renal tumor were registered. 847 of them had a histological proven Wilms Tumor, of whom 637 were unilateral localized, and 173 tumors had an other histology [40 congenital mesoblastic nephroma (CMN), 51 clear cell sarcoma (CCSK), 24 rhabdoid tumor (RTK) and 58 other tumors]. Preoperative chemotherapy in benign tumors was given to 1.3 % of the patients. The main objective of the trial was the randomized question, if the postoperative two drug chemotherapy for stage I in intermediate risk or anaplasia can be reduced from conventional 3 courses to an experimental 1 course without loss of efficacy. RESULTS: 519 patients with unilateral nonmetastatic Wilms did receive preoperative chemotherapy. The histology in this group of patients was of intermediate risk in 469 (90 %) patients, 14 (3 %) tumors were low risk and 36 (7 %) high risk. The stage distribution of the tumors was stage I in 315 (61 %), stage II N- in 126 (24 %), stage II N+ in 25 (5 %) and stage III in 36 (7 %) patients. In 17 (3 %) patients the tumor stage remained unclear. Tumor volume was measured in 487 patients before and in 402 after preoperative chemotherapy. The median tumor volume did shrink from 353 to 126 ml. The amount of volume reduction depends on the histological subtype. The event free survival (EFS) after 5 years was 91 % for all patients with unilateral Wilms tumor without distant metastasis. Randomisation was done in 43.7 % for stage I patients and there was no difference in EFS for both treatment arms (90 versus 91 %). The EFS is identical for patients with stage I and II N- (0.92), as well as for stage II N+ and III (0.82). The tumor volume after chemotherapy is a prognostic factor for intermediate risk tumors with the exception of epithelial and stromal predominant tumors. These two subtypes often present as large tumors, they do not shrink during preoperative chemotherapy but they still have an excellent prognosis. On the other hand the prognosis of patients with blastemal predominant subtype after preoperative chemotherapy is worse than in any other patient group of intermediate risk tumors. There are less blastemal predominant tumors compared to primary surgery, but they are chemotherapeutic resistant selected by the preoperative chemotherapy. CONCLUSION: Patients with unilateral Wilms tumor without metastasis have an excellent prognosis. The post-operative chemotherapy in stage I can be reduced to 4 weeks without worsening treatment outcome. The reduction of the tumor volume could be identified as a helpful marker for stratification of post-operative treatment. Post-chemotherapy blastemal predominant subtype of Wilms tumor has to be classified as high risk tumor. Focal anaplasia has a better prognosis than diffuse anaplasia and will be classified as intermediate risk tumor.     

Pathology of soft tissue sarcomas: 238 cases of the childhood tumor registry

Until April 1981 malignant soft tissue sarcomas were registered from 238 patients. Rhabdomyosarcoma was the most common tumor (115/238 = 48.3%). The embryonal subtype was predominantly seen among the rhabdomyosarcomas (83/115 = 72.2%). Rhabdomyosarcomas were localized most frequently in the head and neck area (40/115 = 34.8%), followed by genitourinary system (15/115), pelvis soft tissue (12), abdomen (10) and extremities (10). Non-rhabdomyosarcomatous soft tissue sarcomas (123/238 = 51.7%) were synovial sarcomas (20 = 8.4%), fibrosarcomas including spindle cell sarcoma (17 = 7.4%), leiomyosarcomas (12 = 5.0%), malignant tumors of the vascular system (11 = 4.6%) and neurofibrosarcomas (9 = 3.8%). Other types of sarcoma were extremely rare. 42 (17.6%) of all soft tissue sarcomas could not be classified histogenetically. Rhabdomyosarcomas could be diagnosed much more accurately (105/115 = 91.3%), compared to all other soft tissue sarcomas (99/121 = 81.8%). At present, the most difficult diagnostic problems remain with the tumors of connective tissue, in particular with fibrosarcomas and with the differential diagnosis of juvenile fibrosarcomas versus juvenile fibromatoses.     

Expression of cytokeratin-18-related tissue polypeptide-specific (TPS) antigen in Wilms tumor

BACKGROUND: So far, there is no approved tumour marker for diagnosis or follow-up in Wilms tumour (WT). Tissue polypeptide-specific antigen (TPS), a cytokeratin 18 proteolytic fragment, has been suggested to be of value in the clinical management of WT patients. Cytokeratin 18 fragments are an early indicator of apoptosis and cytokeratin 18 might influence tumour cell behaviour. We investigated TPS expression in specimens of WT and other paediatric renal malignancies PROCEDURE: Immunoreactivity of WT sections (n = 9), clear cell sarcomas (CCSK, n = 3), and a renal cell carcinoma (RCC), and two pediatric kidney tumour cell lines (WT: SK-NEP-1 and rhabdoid tumour of the kidney: G-401) were investigated using the monoclonal antibody M3. Additionally, immunoblotting and RT-PCR analysis were performed. Cell culture supernatants were evaluated for TPS release. Serum TPS was measured in five patients at diagnosis, during chemotherapy and after surgical resection. RESULTS: Moderate to strong immunoreactivity for TPS was found in tubular and blastemal components of nearly all (8/9) WT specimens. This was confirmed by Western-blotting. Cystic and epithelial-like portions of CCSKs and RCC showed distinct reactivity (3/3). The supernatant of G-401 but not of SK-NEP-1 showed a time- and cell number-dependent increase of TPS release. Interestingly, TPS synthesis was demonstrated in SK-NEP-1 cells. Median preoperative serum TPS was elevated (293 U/l) compared to healthy children and lowest after surgical resection (49.5 U/l). CONCLUSIONS: This is the first study demonstrating the synthesis and release of TPS by WTs and other paediatric renal malignancies. Considering the elevated levels of TPS in serum of these patients, a further investigation of this marker by larger clinical trials seems to be justified.     

BCOR‐CCNB3 fusion‐positive clear cell sarcoma of the kidney

Clear cell sarcoma of the kidney (CCSK) is the second most common malignant pediatric renal tumor. Two of the recurrent somatic alterations reported in CCSK are BCL‐6 corepressor (BCOR) internal tandem duplication (ITD) and YWHAE‐NUTM2B/E gene fusion. A minority of patients with CCSKs have other rare somatic alterations. We report two patients with CCSK showing BCOR‐CCNB3 (where CCNB3 is cyclin B3) fusion, who had similar clinical presentation of a large renal mass with tumor thrombus extending through the inferior vena cava into the right atrium and a favorable response to chemotherapy. We recommend BCOR‐CCNB3 fusion testing for all patients with CCSK who lack BCOR‐ITD or YWHAE‐NUTM2B/E gene fusions.     

Solid tumors in the neonatal period

From 1972 to 2000, 123 patients with solid tumors whose complaints had started in the first 28 days of life were retrospectively evaluated. Fifty-five patients were diagnosed in the first 28 days and 68 patients were diagnosed after 28 days. In the former group, 85.5% of patients had symptoms in the first day of life. In the latter group, 77.9% had the onset of symptoms in the first day. Tumor subgroups in the neonatal period included teratoma (34), neuroblastoma (11), rhabdomyosarcoma (3), Wilms tumor (1), and retinoblastoma (3), and the others (3). Three patients had other, less common tumors. In the second group the numbers were the following: for teratoma (32), neuroblastoma (15), germ cell tumors other than teratomas (8), rhabdomyosarcomas (4), the other soft tissue sarcomas (3), Wilms tumor (1), retinoblastoma (1), and other, rare tumors (4). There were 22 malignant tumors in the first group, and 44 in the second group. Fourteen patients in the first group died in the early postoperative period or with progressive disease. Nineteen of 44 patients died in the second group. Overall survival rates were 24.9% and 51.6% in first and second groups, respectively (p = 0.015). Event-free survival rates were 14.7% and 47.7% in these groups, respectively (p = 0.0063). This is the first report comparing clinical features and prognosis of tumors diagnosed in the first 28 days of the life with those diagnosed after 28 days. The prognosis was worse in infants diagnosed in the first 28 days of life.     

Cancer in children with celiac disease. Gluten-sensitive enteropathy in a boy operated for Wilms tumour

In adults untreated coeliac disease (CD) is associated with a wide variety of malignant complications. The overall mortality in CD is approximately twice that of the general population. The excess deaths are due mainly to intestinal lymphoma. In Europe, only 26 cases of CD and cancer in children have been published. There is evidence that cancer and CD in children are underreported. We report a case of Wilms tumour in a child who developed CD. As a neonate the boy had been successfully operated for congenital mesoblastic nephroma. Gluten was introduced in his diet at age of 12 months. He developed vomiting, abdominal distention ad hypertransaminosaemia. Up to the age of 16 months he had lost 1500 g and coeliac crisis was diagnosed (IgAEMA titre 1:50 and in the duodenal biopsy specimen there was crypt hyperplastic total villous atrophy). Symptoms improved rapidly when gluten-free diet was initiated, and 4 years later, clinical and serological findings were normal. Wilms tumour accounts for 6% to 7% of all childhood malignancies. There are no reports in MEDLINE about coeliac disease in patients who have been operated for the tumour. This seemed intriguing because prevalence of gluten-sensitive enteropathy calculated for Europe varies between 1/100 and 1/300.     

Nephrogenic Rest Associated with a Mesoblastic Nephroma—What does it Tell Us?

A 3-year-old girl presented with a tumor in the right kidney that was found to be a mesoblastic nephroma on histological examination. In addition, between the tumor and renal parenchyma there was a large perilobar sclerosing nephrogenic rest—a finding that has rarely been reported previously in non-Wilms renal tumors of childhood. We believe this supports the theory that both mesoblastic nephroma and Wilms tumor arise from the developing kidney but the key difference is the time point at which induction of neoplasm occurs.     

Ultrasound differential diagnosis of kidney tumors in childhood

Between 1979 and 1989 21 renal tumors (8 girls and 13 boys) were diagnosed and treated in the Pediatric Hospital of the University of Erlangen. Additionally, there was evidence of nephroblastomatosis in 5 children with Beckwith-Wiedemann Syndrome and hemihypertrophy. One of these infants developed a Wilms' tumor at the age of 3 1/2 years. The most frequent tumor was the Wilms' tumor, which was diagnosed in 14 children. Wilms' tumor are sonographically well delineated, round or oval tumors which often enclose small cysts (72%) but rarely calcifications (5%) and show inhomogenous liver like echogenicity. Metastasis in liver, spleen or abdomen occurred in 2 infants. The most frequent renal tumor in neonates was the mesoblastic nephroma (3 infants). All mesoblastic nephromas were well delineated round tumors with inhomogenous echo-texture and equal or increased echogenicity in comparison to the liver. They often enclosed small cysts but no metastasis or calcifications. Angiomyolipomas of the kidneys could be diagnosed in two children with tuberous sclerosis. These tumors were echogenic nodules spread all over the kidney. We found multilocular nephroblastomas with multiple irregularly delineated cysts in one child. In an other child multiple renal lymphomas simulating solid tumors with liver-like echogenicity could be found.     

Aberrant Immunohistochemical Expression in Nonrhabdomyosarcoma Soft Tissue Sarcomas of Infancy: Retrospective Review of Clinical Material

Malignant soft tissue tumors other than rhabdomyosarcoma (RMS) are uncommon in infancy, representing approximately 5% of pediatric sarcomas. The pathological categorization of non-RMS soft tissue malignancies from these young patients is complicated by variation in both morphologic and immunohistochemical features. A search covering an 11-year period identified 19 patients presenting at birth or in infancy with a clinical or referral diagnosis of soft tissue sarcoma. After histologic and immunohistochemical review, nine of these tumors were classified as primitive neuroectodermal tumor (PNET), three as infantile hemangiopericytoma (HPC), two as infantile fibrosarcoma (FS), and five as undifferentiated sarcoma. Those identified as undifferentiated sarcomas showed an atypical spindle and ovoid cell morphology, with cellular pleomorphism and high mitotic rate, but lacking the fascicular growth pattern of classic infantile fibrosarcoma. Immunohistochemical staining in this group showed variable weak positivity for a range of markers (desmin, smooth muscle actin, Myo-D1, PGP, NSE, S100, CO56, cytokeratin, and CD99), and did not fit readily into any distinct diagnostic category. In this series, tumors classified as soft tissue PNETs had a poor prognosis despite aggressive treatment. However, once RMS, PNET, and other rare specific lesions are excluded, the remaining undifferentiated sarcomas, despite their unusual morphology and immunohistochemistry, appear to behave in a similar favorable manner to infantile fibrosarcoma.     

Pretreatment, ultrasound-guided cutting needle biopsies in childhood renal tumors

BACKGROUND: The current International Society of Paediatric Oncology (SIOP)-10 protocol does not allow pretreatment histological classification of low-stage renal tumors in children for fear of needle tract recurrences. The aims of this retrospective study were to evaluate the safety, sensitivity, and specificity of ultrasound-guided cutting needle biopsies (UCNB) performed at our institution in pediatric patients with renal tumors. PROCEDURE: Of 28 pediatric patients presenting with a renal tumor between 1988 and 1996, 25 underwent biopsy with the Biopty biopsy instrument (needle diameter 1.2 mm). The preoperative biopsy and nephrectomy slides were reviewed by a SIOP reference pathologist. The patients' hospital records were reviewed and biopsy complications were noted. RESULTS: At review of the nephrectomy slides, the diagnoses were: Wilms tumor (16 patients), with anaplasia in one case, rhabdoid tumor (2 patients), neuroblastoma (2 patients), mesoblastic nephroma (2 patients), clear cell sarcoma (1 patient), malignant teratoma (1 patient), and renal cell carcinoma (1 patient). No needle tract recurrence or other major complication was observed. The only complication was local pain at the biopsy site, which occurred in 24% (6/25) of the cases. The sensitivity of UCNB was 76% (19/25); five biopsies did not yield diagnostic material and one was not concordant. All cases of Wilms tumor were correctly diagnosed by UCNB, but only 33% (3/9) of the other tumors. CONCLUSIONS: In all cases of Wilms tumor a correct diagnosis was made. The overall sensitivity was 76%. UCNB proved to be a safe procedure that was not associated with needle tract recurrence or other serious complications.     

Developmental Pattern of Thy-1 Immunoreactivity in the Human Kidney and the Application to Pediatric Renal Neoplasms

The localization of Thy-1, a surface membrane lipoglycoprotein, was investigated using a monoclonal antibody specific for human Thy-1 (HB-2S-1). The localization of Thy-1 during development was established in a series of five fetal, three childhood, and two adult normal kidneys. In this series, Thy-1 immunolocalization progressed from mesangial and endothelial cell staining in the 16- to 17-week fetuses to similar staining along with staining of the parietal epithelium of the capsule and proximal tubule staining in the 20- to 24-week fetuses. Glomerular mesangial cell and endothelial cell staining was absent by 9 months postnatally when the adult pattern of staining was apparent. The localization of Thy-1 during development was also compared with a series of pediatric renal tumors including 14 Wilms' tumors, 3 congenital mesoblastic nephromas, 1 clear cell sarcoma, and 1 pediatric renal cell carcinoma. Thy-1 staining was demonstrated in epithelial tubules of Wilms' tumors and in the spindle-shaped cells of congenital mesoblastic nephroma correlating with Thy-1 immunoreactivity in the kidney proximal tubule and fetal medullary stroma, respectively. Thy-1 staining was absent in the anaplastic epithelial Wilms' tumor, the renal cell carcinoma, and the clear cell sarcoma. This staining pattern fails to provide evidence that these tumors may arise from the medullary mesenchyme or the differentiated     

Flow cytometric analysis of DNA ploidy in 62 patients with Wilm's tumor

Flow cytometric analysis of DNA ploidy was done on nuclei extracted from paraffin-embedded tissue blocks from 62 patients with Wilms' tumor, the largest series reported to date. Thirty-eight tumors were aneuploid and 24 were diploid; there were no tetraploids. Sixty-seven percent of the diploids and 44.7% of the aneuploids survived; the difference was statistically significant (P <0.01). The 2 congenital mesoblastic nephromas were diploid; the only 2 adult patients were aneuploid. Aneuploids comprised 75% of those presenting in stage III/IV and 75% of the anaplastic tumors. Genetic heterogeneity, never before reported in Wilm's tumor, was found in 2 patients. Aneuploidy was an ominous prognostic factor, particularly when combined with tumor stage and histological grade. Offprint requests to: M. Rohatgi     

儿童原发性恶性非肾母细胞瘤性肾脏肿瘤诊治特点

目的 探讨儿童原发性恶性非肾母细胞瘤性肾脏肿瘤的临床诊治特点.方法 回顾性分析1993年4月至2008年1月问收治的11例儿童原发性恶性非肾母细胞瘤性肾脏肿瘤患儿的临床资料.根据临床表现及术前影像学检查并于术前行穿刺活检,治疗方法主要为术前介入和/或全身化疗、手术切除、术中热灌注化疗和术后化疗.结果 肾细胞癌6例,无瘤长期(平均32个月)生存率66.7%.中胚性肾瘤3例,均获3年以上无瘤生存.肾透明细胞肉瘤1例,术后复发死亡.肾横纹肌样瘤1例,术后化疗2个月复发,结论儿童原发性恶性非肾母细胞瘤性肾脏肿瘤发病率低,临床表现与肾母细胞瘤相似,术前诊断较为困难,其中肾细胞癌发病年龄多为年长儿,而肾透明细胞肉瘤、中胚层肾瘤和肾横纹肌样瘤则多见于小婴儿.经过多项系统性治疗,中胚层肾瘤预后较佳,肾细胞癌次之.     

儿童非横纹肌软组织肉瘤临床预后因素及治疗对策

目的 分析18岁以下儿童和青少年的非横纹肌肉瘤的生存率,并探讨常见肿瘤的治疗策略。方法 对1989年1月到2002年12月治疗并随访的67例非横纹肌肉瘤病例的资料进行分析,其中滑膜肉瘤16例,恶性纤维组织细胞瘤9例,纤维肉瘤9例,脂肪肉瘤7例,骨外尤文氏肉瘤/原始神经外胚叶瘤7例,腺泡状软组织肉瘤6例,平滑肌肉瘤4例,恶性外周神经鞘瘤、透明细胞软组织肉瘤、血管肉瘤各2例,上皮性软组织肉瘤、促纤维增生性小圆细胞肿瘤、恶性肾外横纹肌样肿瘤各1例。引入年龄、性别、肿瘤大小、外科病理分期、是否接受化疗和放疗等因素,应用SPSS10.0统计软件,采用COX回归和χ^2检验进行统计学分析。结果 影响非横纹肌肉瘤生存率的唯一临床因素是外科病理分期。手术完全切除比肿瘤残留或转移者的生存率更高,Ⅰ、Ⅱ期和Ⅲ、Ⅳ期的2年EFS分别为89.74%和17.86%,差异有统计学意义。无肿瘤残留者生存率高于肿瘤残留或不能切除者。结论 儿童和青少年非横纹肌软组织肉瘤罕见,各肿瘤的临床特征不同,尚无统一治疗方法。治疗原则仍以达到无肿瘤残留为目标的外科手术治疗为主;除尤文氏瘤/原始神经外胚叶瘤和滑膜肉瘤已经证实化疗有效外,其他肿瘤的术后辅助化疗和放疗尚存在争议。新辅助化疗对于部分不能切除的肿瘤可以提高手术切除率。成立全国性的协作组可以尽快积累病例,增加治疗经验,制定规范的治疗方案,是改善儿童非横纹肌软组织肉瘤疗效的有效途径。     

Cancer in infants: a review of 82 cases

Cancer occurring in infants often has clinical and biological properties that are different from those of the same histologic type of cancer occurring in older children. The histologic distribution of cancers in infants and that in older children are also different. The aim of this study was to find these differences between infants and older children, and to compare the percent distribution of infant cancer subtypes with that reported by other countries. The authors collected infant cases diagnosed as having cancer from the database of the Cancer Registry in our Medical Center between 1995 and 2001. Subjects were selected subjects from inpatient logs, and their medical records were reviewed. Eighty-two infants (40 males and 42 females), including 12 neonates, were diagnosed with cancer over this 7-year period. Acute leukemia was diagnosed in 21 infants (25.6%; acute myeloid leukemia in 12, and acute lymphoblastic leukemia in 9), retinoblastoma in 14 (17.1%), neuroblastoma in 12 (14.6%), brain tumor in 9 (11.0%), germ cell tumor in 8 (9.8%), renal cancer in 8 (Wilms tumor 3, mesoblastic nephroma 1, renal sarcoma 1, rhabdoid tumor 3), hepatoblastoma in 5 (6.1%), and soft tissue sarcoma in 5 (rhabdomyosarcoma 1, fibrosarcoma 3, other sarcoma 1). The overall disease-free survival rate was 61.0% (50/82) with a median follow-up duration of 6.8 years for the survivors. The 4 most common types of cancer occurring in infants are the same in the present series and in most larger childhood cancer series reported by other countries; but rank differently. In this study there were more infants with acute leukemia and retinoblastoma, and less with neuroblastoma. The prognosis is poor for infant leukemia and rhabdoid tumor, while it is good for embryonal tumors and germ cell tumors occurring in infancy.