Results of hepatic resection for sarcoma metastatic to liver

Clinical manifestations and prognostic factors in patients with gastrointestinal stromal tumors

AIM: To investigate the incidence of CD117-positive immunohistochemical staining in previously diagnosed GI tract stromal tumors (GIST) and to analyze the tumors’ clinical manifestations and prognostic factors.

METHODS: We retrospectively reviewed 91 cases with a previous diagnosis of GI stromal tumor, leiomyoma, or leiomyosarcoma. Tissue samples were assessed with CD117, CD34, SMA and S100 immunohistochemical staining. Clinical and pathological characteristics were analyzed for prognostic factors.

RESULTS: CD117 was positive in 81 (89%) of 91 tissue samples. There were 59 cases (72.8%) positive for CD34, 13 (16%) positive for SMA, and 12 (14.8%) positive for S100. There was no gender difference in patients with CD117-positive GIST. Their mean age was 65 years. There were 44 (54%) tumors located in the stomach and 29 (36%) in the small intestine. The most frequent presenting symptoms were abdominal pain and GI bleeding. The mean tumor size was 7.5 ± 5.7 cm. There were 35 cases (43.2%) with tumors > 5 cm. The tumor size correlated significantly with tumor mitotic count and resectability. Tumor size, mitotic count, and resectability correlated significantly with tumor recurrence and survival. There was recurrent disease in 39% of our patients, and their mean survival after recurrence was 16.6 months. Most recurrences were at the primary site or metastatic to the liver. Twenty-six percent of our patients died of their disease.

CONCLUSION: Traditional histologic criteria are not specific enough to diagnose GIST. This diagnosis must be confirmed with CD117 immunohistochemical staining. Prognosis is dependent on tumor size, mitotic count, and resectability.

Surgical treatment of hepatic and pulmonary metastases from non-colorectal and non-neuroendocrine carcinoma

BACKGROUND

Surgical resection is standard treatment for colorectal and neuroendocrine liver metases provided the tumor can be removed completely. The same is true for isolated pulmonary metastases. To date, only few reports have addressed the value of surgical resection of organ metastases from other solid tumors.

METHODS

The literature was searched by Medline, conference proceedings and cross-referencing of published articles for information pertaining to the long-term results of surgical treatment of non-colorectal and non-neuroendocrine (NCNN) liver or lung metastases.

RESULTS

Resection of hepatic and pulmonary metastases is increasingly performed in non-colorectal and non-neuroendocrine malignancies. Mortality and morbidity of hepatic and pulmonary resection are low and 5 year survival can be expected to reach some 20-30 percent, irrespective of the histological type of the primary tumor.

CONCLUSION

Resection of hepatic or pulmonary metastasis should be considered in all patients with low operative risk provided that complete resection is possible.

Metastasectomy for limited metastases from soft tissue sarcoma

The development of metastatic soft tissue sarcoma (American Joint Committee on Cancer stage IV) is associated with a poor prognosis. Surgical resection of isolated solitary or multiple metastases is the only curative treatment; all other forms of treatment are considered palliative. As with all surgical procedures, patient selection is important to maximize the clinical benefit of metastasectomy and to minimize the risk for treatment-related morbidity. Over the past decade, nonresectional ablative approaches have been developed to manage visceral metastatic disease. These ablative procedures include cryosurgery, radiofrequency tumor ablation, and alcohol injection. All such procedures are considered investigational; outcome should be compared to that achievable with traditional surgical metastasectomy. The optimal sequence of treatments and role for perioperative (combined with metastasectomy) chemotherapy are unknown. Given the potential curative nature of metastasectomy, all patients with metastatic soft tissue sarcoma should be evaluated for the possibility of surgical resection. Patients with good performance status who have radiographically resectable disease should be considered for metastasectomy.

The GIST of targeted cancer therapy: a tumor (gastrointestinal stromal tumor), a mutated gene (c-kit), and a molecular inhibitor (STI571)

Although gastrointestinal stromal tumor (GIST) is the most frequent mesenchymal neoplasm of the gastrointestinal tract, until recently it has been an obscure disease. Now, there is widespread scientific and clinical interest in GIST because its principal pathogenetic defect has been identified and a specific molecular inhibitor of GIST has been developed. Most GISTs contain a gain-of-function mutation in the c-kit proto-oncogene. Mutation results in constitutive activation of the Kit receptor tyrosine kinase, which induces cellular proliferation. STI571 is an oral agent that selectively inhibits Kit. It is a landmark development in cancer treatment and marks a new era of targeted molecular therapy. Its efficacy proves that a specific inhibitor can counteract the effects of a genetic defect responsible for neoplasia. Although STI571 was first applied to GIST only 2 years ago, it has already revolutionized the treatment of patients with metastatic disease and is also currently being tested as an adjuvant therapy after the resection of primary GIST.

Clinical management of gastrointestinal stromal tumors: before and after STI-571

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. Until recently, surgery has been the only effective therapy for GIST. However, even after complete resection of tumor, many patients still eventually die of disease recurrence. Conventional chemotherapy and radiation therapy have been of limited value. Within the last few years, it was discovered that most GISTs have a gain-of-function mutation in the c-kit proto-oncogene. This results in ligand-independent activation of the KIT receptor tyrosine kinase and an unopposed stimulus for cell growth. STI-571 is a small molecule that selectively inhibits the enzymatic activity of the ABL, platelet-derived growth factor receptor, and KIT tyrosine kinases and the BCR-ABL fusion protein and is a landmark development in cancer therapy. Its clinical development marks a new era of rational and targeted molecular inhibition of cancer that emanates from direct collaborations between scientists and clinicians. It provides proof of the principle that a specific molecular inhibitor can drastically and selectively alter the survival of a neoplastic cell with a particular genetic aberration. The advent of STI-571 has markedly altered the clinical approach to GIST. It has proven to be effective in metastatic GIST and is also under investigation as a neoadjuvant and adjuvant therapy.