Wilms' tumor--model of a curable pediatric malignant solid tumor

Pediatric surgical oncology: A brief overview of where we have been and the challenges we face

The evolution of the treatment of pediatric solid tumors has been one of progressive improvements in survival. With the advent of pediatric cooperative groups, a systematic approach has brought integrated multidisciplinary care to childhood cancer patients. Improved medical regimens and advances in the basic understanding and characterization of molecular biology of individual tumors continues to bring new treatment options. As long term survival has improved, a greater appreciation of the late effects of treatment has led to increase awareness and intervention for things like infertility. The surgeon remains a critical member of the treatment team. Surgical treatment techniques continue to evolve and the role of surgery in each tumor type is continually redefined. It is incumbent on the treating surgeon to know the treatment guidelines for each case in order to provide the patient with the best opportunity for a successful outcome.

Clinico-immunological response to intratumoral versus intravenous neoadjuvant chemotherapy in advanced pediatric solid malignancies

Background:

There is minimal literature on the use of intralesional chemotherapy in the pediatric age group. We undertook this present study to evaluate the two modalities (intratumoral and intravenous) of giving chemotherapy in terms of toxicity of chemotherapy, hematological parameters, efficacy of chemotherapy in reduction in volume of the tumor as well as resectability of tumor with special emphasis on immunological parameters.

Materials and Methods:

Advanced cases of Wilms’ tumor and Neuroblastoma were included in the study. Intratumoral chemotherapy was given through 25 G spinal needle under aseptic precautions and ultrasound guidance in the same dose as in systemic chemotherapy. Intravenous group was given chemotherapy in the usual way. Reassessment was carried out after every course of chemotherapy.

Results:

Group A included 16 cases of Wilms’ tumor and 6 cases of neuroblastoma. In group B, there were 14 cases of Wilms’ tumor and 8 of neuroblastoma. Vomiting, diarrhea, mucositis, and thrombophlebitis were more common in the intravenous group (P<0.05). The fall in Immunoglobulin A, Immunogloblulin G, Immunoglobulin M, and T-cell rosetting was more common in the intravenous group (P<0.05). Seventy percent of patients had completely resectable tumor at the end of 6 doses of intratumoral chemotherapy as compared to 50% resectability in the intravenous group (P<0.05).

Conclusion:

Intratumoral chemotherapy, besides causing less of the adverse effects and increasing the resecability rate, also causes less suppression of the immune system. This may be offered as an alternative safe and effective modality of treatment for advanced solid tumors.

[Congenital urogenital malformations associated with nephroblastomas. Long-term results of a study in Erlangen]

BACKGROUND

Wilms' tumors are highly malignant tumors of the kidneys and are among the most frequent solid tumors of childhood, which are diagnosed for the most part before the 5th year. Various congenital anomalies are associated with a genetic predisposition and thus an increased risk of developing a Wilms' tumor.

PATIENTS AND METHODS

As part of a retrospective analysis, the records from 1965 to 2003 of 66 patients with histologically confirmed Wilms' tumor were reviewed. The aim of this study was to determine the incidence and type of different urogenital malformations as well as the genetic mutations and overall survival in this patient group.

RESULTS

The patient cohort comprised 66 patients with histologically confirmed Wilms' tumor: 35 male patients (53%) and 31 female patients (47%). The overall survival after 10 years was 89.4%. All patients underwent radical nephrectomy: transperitoneal approach in 63 and lumbar approach in 3 patients. Eleven (16.7%) patients had diverse urogenital anomalies. A cytogenetic investigation was performed in 38 patients that revealed no pathological findings. The results of molecular genetic testing of tumor specimens were available for seven patients: a genetic mutation was detected in one case (heterozygous mutation R394 in exon 9 of the WT1 gene) which had already been described in the literature in conjunction with Denys-Drash syndrome. Hemihypertrophy with Beckwith-Wiedemann syndrome was present in two (3%) patients.

CONCLUSION

In patients with urogenital malformations and Wilms' tumor, it would be important to carry out further molecular genetic testing to identify possible WT1 gene mutations. Close interdisciplinary cooperation between urologists, specialists in human genetics, and pediatricians is imperative.

The relationship between microsubstaging variables, age at diagnosis, and tumor weight of children with stage I/favorable histology Wilms' tumor. A report from the National Wilms' Tumor study

BACKGROUND

The purpose of this study was to determine the relationship between histologic microsubstaging variables, patient age, and tumor specimen weight in patients with Stage I/favorable histology Wilms' tumors.

METHODS

The authors reviewed all randomized patients from the Fourth National Wilms' Tumor Study, who had Stage I/favorable histology Wilms' tumors evaluated for one or more of the microsubstaging variables: (1) the presence of an inflammatory pseudocapsule, (2) renal sinus invasion, (3) tumor in the intrarenal vessels, and (4) tumor capsule invasion. The authors determined the correlation between microsubstaging variables and age at diagnosis or tumor specimen weight.

RESULTS

Patients who were younger than 2 years of age at diagnosis were significantly more likely to have all negative microsubstaging variables. Patients who had tumors weighing less than 550 g were more likely to have all negative microsubstaging variables. However, neither renal sinus invasion nor tumor in the intrarenal vessels was more frequent in tumors weighing more than 550 g.

CONCLUSIONS

An age at diagnosis of younger than 2 years and a tumor specimen weight of less than 550 g are highly correlated with the absence of adverse microsubstaging variables. The clinical variables of age at diagnosis and tumor specimen weight, compared with the assessment of microsubstaging variables, have the practical advantage of being more objectively determined and not requiring a central pathologic review for confirmation.

Wilms' tumor

In the last 2 decades, important advances in the treatment of Wilms' tumor have been made. The remarkable improvement in survival in these patients has been the product of new surgical techniques, classification of the tumors into prognostic stages upon initial presentation and the tailoring of chemotherapy and radiation therapy thus permitted. A brief historical perspective is presented with a review of the current treatment and ongoing studies.

Improved survival for children with anaplastic Wilms' tumors

Combined modality treatment has resulted in cure rates of approximately 80% for children with Wilms' tumor. According to the National Wilms' Tumor Studies (NWTS), a group of patients with histologic features of anaplasia or sarcomatous Wilms' tumors (malignant rhabdoid tumors and clear cell sarcomas) were less responsive to vincristine and actinomycin. The survival rate of patients in this group with unfavorable histologic conditions was 54% compared with 90% for those with favorable histologic conditions. We have reviewed 80 consecutive cases of Wilms' tumor treated with a minimum follow-up interval of 5 years. Two pathologists independently reviewed all histologic specimens that were initially classified as having unfavorable histologic conditions and specimens from children with favorable histologic conditions who subsequently relapsed. One of 13 children with favorable histologic conditions had recurrent disease that was found to have unfavorable histologic conditions on rereview. All five patients with sarcomatous Wilms' tumor had a rapidly progressive course. Treatment of eight children with anaplastic Wilms' tumor with vincristine, actinomycin, cyclophosphamide, and abdominal radiation resulted in good disease-free and overall survival rates (5-year survival rate, 87.5%) that were not significantly different from children with tumors having favorable histologic conditions (5-year survival rate, 94%). All children with sarcomatous histologic conditions, however, did not to respond.

Relapse-associated variables in stage I favorable histology Wilms' tumor. A report of the National Wilms' Tumor Study

All 24 cases of confirmed and evaluable Stage I favorable histology (FH) Wilms' tumor (WT) relapsing to date on the Third National Wilms' Tumor Study (NWTS-3) were compared with 48 matched control subjects who had not relapsed for at least 2 years after diagnosis. Fifteen of the clinical and pathological variables studied, including patient age and tumor size, had no significant relationship to the outcome of this study. Four histologic features, all related to the degree of tumor extension within the "tumor-kidney unit" proved to be significantly associated with relapse. These were (1) invasion of the tumor capsule, (2) presence of an "inflammatory pseudocapsule," (3) renal sinus invasion, and (4) tumor in intrarenal vessels. One or more of these features was present in 100% of relapsed cases (excluding one for which two variables were unevaluable), but occurred in only 46% of controls (P less than 0.0002). Therefore, no relapses occurred in the NWTS-3 when all four variables were negative. This result was confirmed by a review of all Stage I cases in the NWTS-1 who had relapsed and who were treated by single-agent chemotherapy. Again, no relapses occurred when all four factors were negative. These results demonstrate the feasibility of "microsubstaging" and could serve as a basis for future refinements of therapy for Stage I favorable histology Wilms' tumor.

Wilms' tumor--treatment and results: a five-decade experience

During the past 53 years, 105 patients with Wilms' Tumor have been treated at the Children's Hospital of Buffalo. Prospective and retrospective staging of these cases has allowed comparison with other reported series. All-stage survival improved from 37% with operation alone to 46% with operation and planned radiotherapy. During the past 22 years, with the addition of adjunctive chemotherapy, all-stage survival is now 80% with lesser stage survival approaching 100%. Participation in the cooperative National Wilms' Tumor Study has brought the most effective proven treatment to the patient in the shortest period of time.

The diagnosis and management of Wilms' tumor

Wilms' tumor is the most frequent malignant tumor of the kidney in infants and children. Effective treatment requires abdominal exploration with nephrectomy and administration of postoperative combination chemotherapy, with abdominal irradiation employed only for the treatment of microscopic or gross residual abdominal disease. Current therapeutic research is focused on improving therapy for certain patient groups, such as those with sarcomatous tumors, who continue to have a poor prognosis, and designing less toxic treatment programs for those patients who currently have a favorable prognosis.

Late effects of treatment for Wilms' tumor

Twenty-six out of a total of 49 patients who were treated for Wilms' tumor at the Mallinckrodt Institute of Radiology between January 1960 and December 1975 have survived at least five years. The median follow-up time is 153 months (12 years, 9 months). One girl, who received pelvic irradiation, has not reached puberty at age 14, but the other 25 patients are currently in good health and have no major complaints or functional impairments at present. Twenty-one patients have, however, developed some complication at some time since treatment. Serious side-effects requiring hospitalization included one case of pericarditis and one of esophageal varices secondary to portal hypertension. Both these patients, however, had advanced tumors requiring aggressive treatment and their complications should be seen in perspective. There has also been one case of temporary low grade renal failure and one of transient hypertension. More common complications were 14 instances of scoliosis (only three have had any symptoms, however), five of osseous hypoplasia, three of soft tissue hypoplasia, three of liver damage and three of lung damage. There was one case of osteochondroma within a radiotherapy field. The factors pertaining to these complications and the anticancer therapy which preceded them are discussed in detail. We conclude that, whereas structural changes following modern radiotherapy for Wilms' tumor are very common, severe dysfunctions are infrequent. Even more extended periods of observation will be required before the total number of abnormalities is ascertained. However, the striking observation from this study is the lack of late functional effects.

Offspring of patients treated for unilateral Wilms' tumor in childhood

Twenty-seven women and the wives of nine men who survived unilateral Wilms' tumor in childhood had a total of 59 live born offspring. Among the 33 infants born to women who had received orthovoltage abdominal irradiation, ten weighed less than 2500 g at birth and three died during the perinatal period. In addition, one term infant of normal weight died of complications of a breech delivery. Only one of 26 infants born to the wives of Wilms' tumor patients and unirradiated female patients weighed less than 2500 g at birth and none died. The frequency of congenital malformations and spontaneous abortions in this series was not increased, and no offspring has developed cancer. The findings suggest that the risk of Wilms' tumor is low among progeny of survivors of nonfamilial, unilateral lesions. Damage from abdominal irradiation given to girls with Wilms' tumor may predispose them to the subsequent delivery of low birthweight children.

Late effects of treatment of cancer in infancy

Eighty-six children were diagnosed with cancer in infancy, followed for at lest 5 years, and assessed for late effects of disease and therapy. One child subsequently died from respiratory failure and 3 died from second primary cancers. Another patient survived second primary cancers of the skin. The high frequency of new cancers (4 observed, 0.09 expected) was attributable to host susceptibility factors and treatment effects. Kyphoscoliosis was diagnosed in 44 patients, 40 of whom had received radiotherapy to the spine. Other patients had neurologic deficits, pulmonary fibrosis, hypoplastic breasts, bowel adhesions, thyroid nodules, musculoskeletal defects, and liver fibrosis associated with tumor therapy. Sequelae of cancer were more common after treatment in infancy than in later childhood. Improved treatments and knowledge of natural history can reduce adverse effects of therapy.

Preoperative chemotherapy for Wilms tumor

Preoperative chemotherapy was administered to 19 children with Wilms tumor judged clinically to be unresectable at M. D. Anderson Hospital between January 1, 1962, and September 1, 1980. After 2 to 4 doses of vincristine, marked reduction in tumor size occurred in 16 patients. After chemotherapy 16 tumors could be resected completely, another required irradiation to reduce the tumor, and only 2 tumors could not be excised. Pathologically the most dramatic changes occurred in the undifferentiated interstitial stroma, followed next by changes in the nodular blastema. Differentiated elements were apparently not affected. No serious complications were attributed to the preoperative drug treatment. This experience suggests that in selected instances preoperative chemotherapy can affectively facilitate the therapy of Wilms tumor.

An analysis of histology and DNA-ploidy in primary wilms tumors and their metastases and a study of the morphological effects of therapy

In children with Wilms' tumours the length of survival is greatly influenced by success in preventing or controlling metastatic disease. The current study focuses on the morphological aspects of metastases when compared with the primary tumour. In 8 patients it appeared that blastema is the most likely component to metastasize, whereas epithelial and stromal components were hardly, if at all, represented in metastases. Furthermore, flow cytometric DNA ploidy determinations on 4 cases showed that both the primary tumours and the metastases had stemlines in the diploid and low aneuploid (hyperdiploid) range. Finally, in four cases the influence of therapy on morphology of the primary tumours was analyzed. In these cases blastema seemed to be the component most sensitive to therapy. Thus, blastema seems to play a central role in prognosis of Wilms' tumours; either reacting to therapy or, if insensitive, by metastasizing.