Note: Some citations in the text of this section are followed by a level of evidence. The PDQ Pediatric and Adult Treatment Editorial Boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)
Many of the improvements in survival in childhood cancer have been made using new therapies that have attempted to improve on the best available, accepted therapy. Clinical trials in pediatrics are designed to compare potentially better therapy with therapy that is currently accepted as standard. This comparison may be done in a randomized study of two treatment arms or by evaluating a single new treatment, comparing the results with those previously obtained with standard therapy.
Oropharyngeal cancer is uncommon and typically involves patients in the fifth through seventh decades of life; men are afflicted three to five times more often than women.[1,2,3]
Similar to other cancers of the head and neck, tobacco and alcohol abuse represent the most significant risk factors for the development of oropharyngeal cancer.[3,4] (Refer to the PDQ summaries on Hypopharyngeal Cancer Treatment and Lip and Oral Cavity Cancer Treatment for more information.) Other risk factors may include:
Because of the relative rarity of cancer in children, all children with liver cancer should be considered for entry into a clinical trial. Treatment planning by a multidisciplinary team of cancer specialists with experience treating tumors of childhood is required to determine and implement optimum treatment.
Historically, complete surgical resection of the primary tumor has been required to cure malignant liver tumors in children.[2,3,4,5]; [Level of evidence: 3iiA] Complete surgical resection of the primary tumor continues to be the goal of definitive surgical procedures, but surgical resection is often combined with other treatment modalities (e.g., chemotherapy) to achieve this goal.
There are three ways in which surgery is used to treat primary pediatric liver cancer:
Initial surgical resection (alone or followed by chemotherapy).
Delayed surgical resection (chemotherapy followed by surgery).
Orthotopic liver transplantation.
The timing of the surgical approach is critical. For this reason, surgeons with experience in pediatric liver resection and transplantation should be involved early in the decision-making process for determining optimal timing and extent of resection.
If the tumor can be completely excised by an experienced surgical team, less postoperative chemotherapy may be needed. If preoperative chemotherapy is to be administered, it is very important to consult frequently with the surgical team concerning the timing of resection, as prolonged chemotherapy can lead to unnecessary delays and in rare cases, tumor progression.
Early involvement with an experienced pediatric liver surgeon is especially important in patients with PRETEXT stage 3 or 4 disease, patients with involvement of major liver vessels, and patients with low alpha-fetoprotein (AFP) levels. While vascular involvement was initially thought to be a contraindication to resection, experienced liver surgeons are able to perform aggressive approaches avoiding transplantation.[7,8]; [Level of evidence: 3iiA] In a group of adult patients that were initially thought to be nonresectable, 85% of the patients were resected using an aggressive approach to the tumor with a mortality rate of 6%. The resection margins were clear in over 90% of the patients. Accomplishing a complete resection is imperative since rescue transplant of incompletely resected patients has an inferior outcome compared to patients who are transplanted as the primary surgical therapy.