Sex: F, Age: 5 years
Diagnosis: Nephroblastoma (Wilms’ Tumor)
The patient is a 5 year old female, weight 16.7 kg, height 114 cm. Her parents report that the patient had a growth deficit due to cow’s milk intolerance at 9 months. She had her adenoids removed and she was diagnosed with a bilateral inguinal hernia during her last hospitalization.
The patient was brought to the emergency room due to occasional left abdominal swelling.
An ultrasound showed the presence of a solid mass adhered to the top of the left kidney.
After being transferred to other Hospital, the patient had a Total Body CAT scan with contrast medium, a chest x-ray and a range of blood chemistry tests (in her urine: Vanilmandelic acid 7.2 and homovanillic acid 12.5), which allowed a diagnosis of stage I Wilms’ Tumor (the mass was contained and no metastases were found).
The patient was transferred to the Oncology Unit where a catheter was installed to begin chemotherapy in accordance with the International Pediatric Oncology regimen: 4 sessions, two of which with Vincristine 1 mg and Actinomycin D 750 mcg, and 2 with only one medication prior to surgery in week 5, and then 5 more weeks of chemotherapy.
Looking carefully at the attached images, I do agree with the radiologist that the tumor staging is consistent with stage 1. Nevertheless, although there is a high probability that the mass is a Wilms' tumor, the definitive diagnosis and staging could be defined only after a pathological examination of the mass and the lymph nodes.
To assess the actual pathology, the patient should have undergone surgery prior to chemotherapy. This attitude reflects the protocol adopted by American oncologists in the late 1960s, followed by five comprehensive studies, known as the National Wilms' Tumor Study (NWTS), attempting to determine optimal treatment for the different stages of Wilms' tumor. According to NWTS, the initial treatment in cases similar to the case here under discussion, should include surgery, and then followed by chemotherapy only after a definitive diagnosis and staging were determined. NWTS investigators recommended immediate nephrectomy because the administration of prenephrectomy chemotherapy may be associated with the following undesirable outcomes: 1. Administration of chemotherapy to a patient with a benign disease; 2. Administration of chemotherapy to a patient with a different histology type of malignant tumor; 3. Modification of tumor histology; or 4. Loss of staging information.
Contrary to this way of thinking, in the early 1970s a newly established European group called the International Society of Pediatric Oncology (SIOP) conducted comprehensive prospective protocols in which pre-operative chemotherapy was followed by surgery. SIOP hypothesizes that this approach usually results in tumor shrinkage, reducing the risk of intra-operative spill (Lemerle et al., 1976). It is also postulated that the neo-adjuvant therapy will treat micro-metastases, leading to a more favorable stage distribution at the time of surgery. Finally, SIOP have claimed that the risk of non-cancerous lesion is only 1%.
Although the National Wilms' Tumor Study Group and the International Society of Pediatric Oncology differ regarding the merits of pre-operative chemotherapy, outcomes of patients treated with either up-front nephrectomy or pre-operative chemotherapy have been excellent.; children with stage 1 and a favorable histology have 4-5 years event free survival that approaches 90%.
According to SIOP 9 the patient should receive 4 weeks of pre-nephrectomy treatment with vincristine and dactinomycin. However, for selected patients, shorter courses of vincristine/dactinomycin or vincristine alone show equivalent results compared to current regimens (D'Angio, Curr. Opi Urol, 2005).
In my opinion, no further diagnostic or laboratory tests are currently needed in addition to those that have already been done.
Regarding lifestyle, hygiene and diet during and after treatment:
The chemotherapy administered to the patient usually does not cause severe side effects. Thus, we do not limit diet in any way. Nevertheless we instruct our patients' parents to carefully wash all fresh fruit and vegetables, and to try to avoid pastries from restaurants during chemotherapy. In cases where the white cell counts are going down, we recommend avoiding exposure of the child to people, but usually the patient does not need to be in isolation.
We also do not recommend performing physical effort for 6-7 weeks after surgery.
Surgery should be performed by the most experienced team at the patient's institution, either by the surgeons or the urologists; I would also recommend considering fixing the patient's hernias at the time of the nephrectomy.