Long-term survival after high-dose chemotherapy followed by peripheral stem cell rescue for high-risk, locally advanced/inflammatory, and metastatic breast cancer.

Patients with high-risk locally advanced/inflammatory and oligometastatic (≤3 sites) breast cancer frequently relapse or experience early progression. High-dose chemotherapy combined with peripheral stem cell rescue may prolong progression-free survival/relapse-free survival (PFS/RFS) and overall survival (OS). In this study, patients initiated high-dose chemotherapy with STAMP-V (carboplatin, thiotepa, and cyclophosphamide), ACT (doxorubicin, paclitaxel, and cyclophosphamide), or tandem melphalan and STAMP-V. Eighty-six patients were diagnosed with locally advanced/inflammatory (17 inflammatory) breast cancer, and 12 were diagnosed with oligometastatic breast cancer. Median follow-up was 84 months (range, 6-136 months) for patients with locally advanced cancer and 40 months (range, 24-62 months) for those with metastatic cancer. In the patients with locally advanced cancer, 5-year RFS and OS were 53% (95% CI, 41%-63%) and 71% (95% CI, 60%-80%), respectively, hormone receptors were positive in 74%, and HER2 overexpression was seen in 23%. In multivariate analysis, hormone receptor-positive disease and lower stage were associated with better 5-year RFS (60% for ER [estrogen receptor]/PR [progesterone receptor]-positive versus 30% for ER/PR-negative; P < .01) and OS (83% for ER/PR-positive versus 38% for ER/PR-negative; P < .001). In the patients with metastatic cancer, 3-year PFS and OS were 49% (95% CI, 19%-73%) and 73% (95% CI, 38%-91%), respectively. The favorable long-term RFS/PFS and OS for high-dose chemotherapy with peripheral stem cell rescue in this selected patient population reflect the relative safety of the procedure and warrant validation in defined subgroups through prospective, randomized, multi-institutional trials.

Robotic-assisted laparoscopic low anterior resection with total mesorectal excision for rectal cancer.

BACKGROUND: With advanced stereoscopic vision, lack of tremor, and the ability to rotate the instruments surgeons find that robotic systems are ideal laparoscopic tools. Because of its high operating cost, however, robotic surgery should be reserved to procedures in which the technology can be of maximum benefit, usually when precise dissections in confined spaces are required. Because conventional laparoscopic total mesorectal excision is a challenging procedure, we have sought to assess the utility of the DaVinci robotic system in laparoscopic low anterior resections for cancer of the rectum. METHODS: Between November 2004 and May 2005 robotic-assisted low anterior resection with total mesorectal excision was performed on six consecutive patients with rectal cancer. These cases were compared with six consecutive low anterior resections performed with conventional laparoscopic techniques by the same surgeon. RESULTS: There were no conversions in either group. Operative and pathological data, complications, and hospital stay were similar in the two groups. Robotic operations appeared to cause less strain for the surgeon. CONCLUSIONS: Robotic-assisted laparoscopic low anterior resection for rectal cancer is feasible in experienced hands. This technique may facilitate minimally invasive radical rectal surgery.

A carcinoembryonic antigen-secreting adenocarcinoma arising within a retrorectal tailgut cyst: clinicopathological considerations.

Retrorectal tailgut cysts (TGC) develop from postanal fetal gut remnants. They have specific radiological and histopathological features that distinguish them from dermoid cysts, enteric duplication cysts, and teratomas. We report a patient with a carcinoembryonic antigen-producing adenocarcinoma arising within a TGC who underwent resection through a combined anterior laparotomy/posterior pelvic approach. Despite complete resection and delayed but complete functional recovery, diffusely metastatic disease was encountered 6 months after resection. Diagnostic, therapeutic, histopathological, and oncological implications of this illustrative case are discussed. It seems possible to use carcinoembryonic antigen measurements for treatment planning and for assessing treatment response for this rare disease. The described outcome also suggests that TGC can develop malignant degeneration and should be resected at the time of diagnosis.

Mediastinal germ cell tumor in a child with precocious puberty and Klinefelter syndrome.

An 8-year-old boy presented with precocious puberty and a mediastinal mass. A computer search showed that this rare presentation is most common with germ cell tumor of the mediastinum in children with Klinefelter syndrome. The tumor was completely resected after preoperative chemotherapy, and the patient is well 2 years after the operation. In patients with Klinefelter syndrome, germ cell tumors are 50 times more common than in patients without Klinefelter syndrome, usually contain nonseminomatous elements, present at an earlier age, and are seldom testicular in location.

Visceral varicella-zoster after bone marrow transplantation: report of a case series and review of the literature.

OBJECTIVES: Infection with varicella-zoster virus after bone marrow transplantation (BMT) is a common cause of morbidity and mortality. Visceral involvement with varicella-zoster may be incorrectly ascribed to graft-versus-host disease, resulting in delayed diagnosis and misguided therapy. METHODS: A 4-yr retrospective chart review was performed to determine the presenting symptoms and clinical outcome of visceral varicella-zoster virus infection in BMT recipients. RESULTS: Ten BMT recipients who subsequently developed visceral varicella-zoster virus infection were identified. The mean age at diagnosis was 40 yr (range 27-56 yr). Primary hematological malignancies were leukemia (N = 7), myelodysplasia (N = 2), and myelofibrosis (N = 1). Bone marrow transplants in affected patients were autologous (N = 2), related allogeneic (N = 5), or matched unrelated allogeneic (N = 3). The mean time interval from BMT to symptomatic visceral varicella-zoster virus infection was 153 days (range 60-280 days). Presenting symptoms included abdominal pain in all patients, nausea (60%), fever > 38 degrees C (60%), vomiting (50%), pneumonitis (50%), skin rash (40%), and diarrhea (30%). All patients had moderately or profoundly elevated aminotransferases and most had elevated pancreatic enzymes (80%). The mean time interval from the development of abdominal pain to the characteristic skin rash and then diagnosis was 6 and 7 days, respectively (range 4-10 and 4-14 days). Active graft-versus-host disease had previously been documented in five of the eight allogeneic BMT recipients. Immunosuppressive medications were increased at the onset of the abdominal pain in seven of these eight patients for suspected exacerbation of graft-versus-host disease. After recognition of varicella infection, antiviral therapy was promptly initiated; despite this, mortality was still 50%. CONCLUSIONS: Visceral involvement with varicella-zoster virus infection can occur as a late complication after both allogeneic and autologous BMT. In these cases, symptoms of severe abdominal pain with associated nausea, vomiting, and diarrhea and elevated liver and pancreatic enzymes preceded the vesicular skin eruption and were confused with graft-versus-host disease. With the increasing application of high-dose chemotherapy followed by stem cell rescue for both hematological and solid tumors, clinicians should be aware of this potentially treatable and often lethal complication.

Detection of human papillomavirus DNA and oncoprotein overexpression are associated with distinct morphological patterns of tonsillar squamous cell carcinoma.

Human papillomavirus (HPV) DNA has been detected in approximately 15% of squamous cell carcinomas (SCCs) of the head and neck. Recent studies have shown a predilection of HPV for certain anatomical sites, especially the tonsillar region, with viral DNA identified in approximately 60% of SCCs of the Waldeyer's tonsillar ring. This study was undertaken to determine whether there are differences in morphology or in oncogene expression in SCC of the tonsil with and without detectable HPV DNA. Twenty-two SCCs of the tonsil were analyzed for the presence of HPV DNA by polymerase chain reaction (PCR) using both a consensus primer set (My09/My11) and type-specific primers. Viral transcription was established in both primary and metastatic tumors by RNA in situ hybridization. The morphology of invasive SCC was classified into three subtypes: well keratinized (K-SCC), intermediate keratinized (I-SCC), and poorly keratinized (P-SCC). Expression of p53, pRB, and cyclin D1 (bcl-1) were studied by immunohistochemistry. In these cases (6 K-SCCs, 2 I-SCCs, and 14 P-SCCs), HPV DNA was detected in 14 (64%), with 11 containing HPV-16 (10 P-SCCs, 1 I-SCCs, and 0 K-SCCs) and 1 each containing HPV-33, HPV-59, and an unclassified HPV type (all P-SCCs). Viral oncoprotein E6/E7 transcription was demonstrated in 7 of 7 HPV-16-positive tumors. Cyclin D1 protein overexpression was detected in the majority of HPV-negative tumors (7 of 8 cases), whereas it was minimal or absent in 13 HPV-positive tumors. Overexpression of p53 protein was detected in 3 HPV-negative K-SCCs. In the HPV-positive tumors, fewer malignant cells expressed pRB and the staining was less intense than in the HPV-negative cancers. HPV DNA and E6/E7 expression, especially HPV-16, is detected in the majority of tonsillar SCCs and is almost exclusively associated with a poorly keratinized tumor histology. Decreased expression of cyclin D1, pRB, and p53 in tumors with HPV DNA is consistent with the known effects of the viral oncoproteins on the cellular protein. The morphology of the HPV-positive tumors suggests that HPV may have a predilection for a population of nonkeratinizing squamous cells or that the virally transformed cells inhibit keratinization of the tumor cells. Well keratinized tonsillar SCCs lack HPV DNA and are associated with overexpression of cyclin D1 protein and/or p53, suggesting that mechanisms that alter the cell cycle regulatory proteins, either by interaction with viral oncoproteins or by changes in the cellular proteins themselves, is critical for tumorigenesis of tonsillar SCC.

Human papillomavirus (HPV) in head and neck cancer. An association of HPV 16 with squamous cell carcinoma of Waldeyer's tonsillar ring.

BACKGROUND: Certain strains of human papillomavirus (HPV) have been shown to be etiologically related to the development of uterine cervical and other genital cancers, but their role in the development of malignancies at other sites is less well established. Previous studies have shown HPV DNA in tumors of the head and neck, but its prevalence has varied depending on the detection methods and the types of tumor and/or tissue examined. This study was undertaken to estimate the frequency of HPV DNA in squamous cell carcinoma (SCC) at different sites of the esophagus, head and neck and to compare the clinical behavior of HPV positive and negative tumors. METHODS: DNA was extracted from frozen tissue of 167 SCCs of the esophagus, head and neck. The DNA was screened for HPV sequences by polymerase chain reaction with two sets of consensus primers, one to a conserved region in the L1 gene (MY09/ MY11) and the other to a conserved region in the E1 open reading frame (IU/IWDO). The products were run on agarose gels, detected by ethidium bromide staining, and then the gels were subjected to Southern blot analysis and hybridized with probes specific to HPV 6, 16, and 18. All tumors found to be HPV positive with the consensus primers were amplified with type specific primers, and in selected cases the presence of HPV DNA was confirmed by restriction enzyme digestion of the tumor DNA with conventional Southern blot analysis. RESULTS: Overall, HPV sequences were found in 25 of 167 tumors (15%), but HPV was detected most frequently in tumors in Waldeyer's tonsillar ring. In that area, 9 of 15 (60%) were HPV positive. No HPV DNA was detected in 11 esophageal SCCs, 7 tumors of the pharynx/hypopharynx, or 6 pyriform sinus carcinomas. HPV DNA was detected in the following tumor sites: 1 of 28 (3.6%) in the larynx, 1 of 10 (10%) in the oral cavity, 5 of 39 (12.8%) in the tongue, 2 of 15 (13.5%) in the floor of the mouth, 3 of 21 (14.3%) supraglottic, and 1 of 7 (14.3%) in the lip. A high incidence of HPV DNA was also found in metastatic tumors located in cervical lymph nodes for which no primary site was clinically identified (3 of 8, 37.5%). With respect to age, gender, and tobacco and alcohol consumption, analysis of clinical data obtained by retrospective review showed no difference between patients with HPV DNA in their tumors and those in which no HPV was detected. However, HPV positive patients had larger tumors (P = 0.09) and a higher incidence of lymph node metastasis (P = 0.003). In spite of the higher stage of disease at presentation in HPV positive patients, there was no significant difference in 3-year survival rates between HPV positive patients and HPV negative patients (43.1% vs. 48.8%, respectively). Median follow-up was 27 months. CONCLUSIONS: In the head and neck, HPV-associated SCC had site specificity with the viral DNA frequently found in tumors in Waldeyer's tonsillar ring. Patients with HPV positive tumors presented with a higher stage of disease than patients with HPV negative tumors, but there was no significant difference in the 3-year survival rates between these two groups of patients.

Local recurrence in breast cancer: implications for systemic disease.

BACKGROUND: Recurrence in breast carcinoma follows a pattern of growth marked by local, regional, or widespread dissemination. Local recurrence may be the harbinger of systemic disease or failure of local control. Delineation of these processes may have implications in treatment. METHODS: A retrospective review found 1,171 patients with stages I and II breast cancer from 1978 to 1990 treated at the City of Hope Medical Center. RESULTS: Twenty-seven percent (n = 313) of patients developed recurrences. These were classified as local, including chest wall and regional nodes (n = 40), local and distant (n = 63), and distant (n = 210). Mean follow-up was 60 months. Multivariate analysis demonstrates tumor size was not different between the three groups, but the presence of positive lymph nodes was: local = 51%, local and distant = 78%, and distant = 64%. The disease-free interval was longest in the local group (42 months) versus the local and distant group (23 months) and distant group (39 months). Median survival was calculated from the time of recurrence: local = 90 months, local and distant = 26 months, and distant = 16 months. CONCLUSIONS: A group of patients with local recurrence have improved survival and do not develop distant disease. This group may benefit from aggressive surgical treatment to control local disease. These data suggest that a subset of breast tumors can act locally aggressive without metastatic potential.

Primary lymphoepithelioma-like carcinoma of the lung in a child. Report of an Epstein-Barr virus-related neoplasm.

Lymphoepithelioma-like carcinoma (LEC), an undifferentiated carcinoma with pronounced lymphocytic infiltration, often is seen in the nasopharynx as well as in other areas. But such primary pulmonary lung neoplasms in children are rare, and we present the first reported case of primary pulmonary LEC in a child.

Treatment of perianal infection following bone marrow transplantation.

PURPOSE: Bone marrow transplantation (BMT) is often associated with profound neutropenia. Allogeneic transplant recipients also have defects in both humoral and cellular immunity and thus are subject to increased risk of serious, often life-threatening, infection even beyond the period of granulocyte recovery. The current study was undertaken to evaluate patients who required operative intervention for perianal sepsis following BMT. METHODS: The bone marrow transplant database at a single institution was used to identify all patients diagnosed with perianal infections after autologous or allogeneic BMT. Charts were reviewed in a retrospective manner. RESULTS: Over a ten-year period ending in November 1993, 963 BMT were performed at the City of Hope National Medical Center. Twenty-four patients were diagnosed with perianal infections following their transplants. Fifteen patients did not have purulent collections requiring drainage and were treated with antibiotics and supportive measures alone. Nine patients (37.5 percent) required surgical intervention between 10 and 380 days following transplantation. At the time of surgical intervention, seven patients had purulent collections and two patients had acute and chronic inflammation, tissue necrosis, and fibrosis. Of the two patients with an absolute neutrophil count less than 1,000, a purulent collection was found in one of the patients. Cultures taken from perianal abscesses were almost all polymicrobial, and the most common organisms were Escherichia coli, Bacteroides, Enterococcus, and Klebsiella. For those patients undergoing surgical intervention, mean time to complete wound closure by secondary intention was 37.6 days; five patients healed in less than 15 days, two patients healed at 93 and 114 days, and two patients had persistent, open wounds at time of death, which was unrelated to their perianal disease. Five patients were receiving systemic steroids at time of surgical intervention; this did not appear to affect time to wound healing. CONCLUSIONS: Perianal infections are a rare complication of BMT. Majority of these infections are polymicrobial, and organisms isolated are similar to those seen in the perianal infections of nonimmunosuppressed patients. Despite steroid use, granulocytopenia does not exclude the possible presence of purulent collections, and clinical examination should guide the decision for surgical drainage. In general, perianal wound healing is not prolonged in BMT patients.

Survey of physicians' attitudes relative to the field of surgical oncology.

BACKGROUND: Surgical oncology as a distinct field of expertise is fairly young. The current study was designed to gain a better understanding of the attitude of practicing physicians toward the field of surgical oncology. METHODS: Three hundred twenty-seven physicians in the San Gabriel Valley (a suburban area adjacent to Los Angeles) responded to an anonymous survey of opinions regarding surgical oncology. Responses were placed into a computerized database. RESULTS: Of those responding, 179 were primary care physicians, 52 were general surgeons, 78 were gynecologists, and 18 were medical oncologists. Overall, 89% of physicians were familiar with the field of surgical oncology, but only 47% had ever heard of The Society of Surgical Oncology (SSO). Ninety-four percent of the respondents felt that a surgical oncologist should care for patients with complex cancer, and 63% of respondents felt that surgical oncologists should care only for patients with complex cancer. Familiarity with the field of surgical oncology and with the SSO correlated with the percentage of the physicians practice that was cancer related. Only 22% of physicians felt that the field of surgical oncology is redundant to the general surgical specialties. CONCLUSIONS: Results of the survey indicate that there is considerable recognition of the unique expertise of the surgical oncologist by the medical community. Unfortunately, many physicians are not familiar with the SSO. Educating physicians in the community about the SSO may help to further expand the role of the surgical oncologist in the care of the patient with cancer, standardize the expectations of the skills and training of a surgical oncologist, and set a benchmark for the surgical subspecialty.

Heat shock protein 84 forms a complex with mutant p53 protein predominantly within a cytoplasmic compartment of the cell.

Cellular DNA damage results in the increased expression and accumulation of the p53 tumor suppressor protein within the nucleus which leads to cell cycle arrest or apoptosis. In some cases, however, wild-type p53 and some mutant forms of p53 reside in the cytoplasm of cancer cells. To understand the mechanism responsible for its cytoplasmic retention, studies were undertaken to determine if unique proteins form a complex with mutant p53 within the cytoplasm of transformed cells. One protein, with an apparent molecular mass of 92 kDa (p92), was observed to form a complex with a temperature-sensitive mutant p53 (TSp53(Val-135)) in the cytoplasm of transformed rat embryo fibroblasts at the non-permissive temperature. p92 copurified with TSp53(Val-135) on a p53-specific immunoaffinity column and a gel filtration column. The protein was purified to homogeneity and identified as hsp84 by partial amino acid sequence analysis. hsp84 is a member of the hsp90 class of proteins. At the non-permissive temperature, TSp53(Val-135) and hsp84 colocalized in the cytoplasm near the nuclear envelope. At the permissive temperature, TSp53(Val-135) resides in the nucleus and expresses a "wild-type like" conformation. Under these conditions hsp84 continued to reside in the cytoplasm and little or no hsp84 formed a complex with p53. The results suggest that hsp84 binds mutant p53 in a spatial and/or conformation dependent manner.

Compartment syndrome of the leg secondary to leukemic infiltration: a case report and review of the literature.

Leukemic infiltration of muscle is an unusual cause of compartment syndrome. High index of suspicion with early fasciotomy may be the only way to save the leg and prevent life-threatening complications. Biopsy of the muscle should be done when the etiology of the compartment syndrome is not clear. The probable mechanisms and treatment approaches are discussed.

Characterization of human placental insulin-like growth factor-I/insulin hybrid receptors by protein microsequencing and purification.

Protein microsequencing of human placental IGF-I receptors purified by immunoaffinity chromatography using IGF-I receptor specific monoclonal antibody revealed amino acid sequences of both IGF-I and insulin receptors. Since this finding indicated the presence of IGF-I/insulin receptor hybrids, hybrid receptors were further purified by immunoaffinity chromatography using insulin receptor specific monoclonal antibody. The molecular size of the nonreduced hybrid receptor was approximately 350K, indicating that the IGF-I and insulin receptor alpha beta halves were disulfide-linked. The ratio of IGF/insulin binding activity of purified hybrid receptors was approximately 25 when measured using tracer amounts of radioactive ligands. 125I-IGF binding to these receptors was inhibited by IGF-I and insulin with IC50s of approximately 2 and approximately 1000 nM, respectively. 125I-Insulin binding to these receptors was similarly inhibited by IGF-I and insulin with IC50 of approximately 3 nM. Autophosphorylation and kinase activities of the hybrid receptor were stimulated by IGF-I more effectively than insulin in a dose-dependent manner. Thus, the present studies indicate that hybrid receptors purified from human placenta have the functional properties of an IGF-I receptor.

Two new monoclonal antibodies against the alpha subunit of the human insulin-like growth factor-I receptor.

Recently, we have reported three monoclonal antibodies (mAbs) against purified human placental insulin-like growth factor (IGF)-I receptors. These antibodies, in contrast to the well-studied mAb alpha IR-3, stimulate binding of IGF-I and IGF-II to the receptor and DNA synthesis as well [Xiong, et al., Proc. Natl. Acad. Sci. U.S.A. 1992(89), 5356]. Here we describe two additional mAbs, 1H7 and 2C8, against the IGF-I receptor that have characteristics different from either alpha IR-3 or our previously reported mAbs. Both 1H7 and 2C8 bind to the alpha subunit of the IGF-I receptor as determined by immunoblotting. MAb 1H7 inhibited the binding of IGF-I and IGF-II to the IGF-I receptor while 2C8 had no effect on the binding of either ligand to the receptor. When their effects on DNA synthesis were examined using NIH 3T3 cells expressing human IGF-I receptors, 1H7 inhibited basal and IGF-I- or IGF-II-stimulated DNA synthesis whereas 2C8 stimulated basal DNA synthesis but provided no synergism in the presence of IGF-I or IGF-II.

Human insulin receptor beta-subunit transmembrane/cytoplasmic domain expressed in a baculovirus expression system: purification, characterization, and polylysine effects on the protein tyrosine kinase activity.

We have expressed, purified, and characterized the insulin receptor protein tyrosine kinase (PTK) retaining the transmembrane and downstream domains. The proteins expressed in insect cells using a baculovirus expression system were identified as membrane-bound by immunofluorescence staining and biochemical characterization. One-step purification by immunoaffinity chromatography from Triton X-100 cell extracts resulted in a approximately 360-fold increase in the specific kinase activity with a yield of approximately 50%. An appMr = approximately 60,000 protein was the major component identified by both silver staining of the purified enzyme and immunostaining of the crude extracts after separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. Using nondenaturing conditions, the molecular weight was estimated to be approximately 250,000 and approximately 500,000 by glycerol gradient centrifugation and gel permeation chromatography, respectively, suggesting that oligomers of the beta-subunit domains such as tetramers and octamers are formed. The basal PTK activity of this enzyme was much higher than those of previously reported soluble-form insulin receptor PTKs expressed in insect cells or the native receptor. Km and Vmax for two substrates, src-related peptide and poly(Glu, Tyr) (4:1), were 2.4 mM and 2.5 mumol min-1 mg-1 and 0.26 mM and 1.2 mumol min-1 mg-1, respectively. Specific activities measured under two previously reported conditions using histone H2B as a substrate were 100 or 135 nmol min-1 mg-1, in contrast to those of soluble PTKs which were reported to be 20 or 70 nmol min-1 mg-1, respectively. The purified enzyme was autophosphorylated at Tyr residues. Autophosphorylation activated the enzyme approximately 3-fold.(ABSTRACT TRUNCATED AT 250 WORDS)

Extended indications for functional limb-sparing surgery in extremity sarcoma using complex reconstruction.

From 1980 to 1991, 29 patients underwent complex reconstruction following extremity sarcoma resection. Soft tissue was the site of origin in 15 patients (52%) and bone was the site of origin in 14 patients (48%), with 20 sarcomas (69%) in the lower extremity. Resection consisted of the following procedures: extended anatomical soft-tissue resections (21 patients [72%]), bone resections (18 patients [62%]), and joint resections (14 patients [48%]). Reconstruction involved the following: myocutaneous flaps (20 patients [69%]), joint prosthesis (eight patients [28%]), and bone reconstruction (15 patients [52%]). There was no surgical mortality; one patient required an amputation owing to surgical complications. The site of the first failure was local (four [31%] of 13 patients), lung (five patients [38%]), others (four patients [31%]). At a median follow-up of 23 months, 18 patients (62%) had no evidence of disease, 27 (93%) had no local disease, 21 (72%) had good extremity function, three (10%) had major disabilities, and five (17%) underwent amputations. Local control improved when the margin of resection was larger than 10 mm. Disease-free survival was 67% at 3 years. Overall survival was 51% at 5 years. Tumor size was an independent predictor of overall survival. Local recurrence did not affect overall survival.

Identification and cloning of a novel amplified DNA sequence in human malignant fibrous histiocytoma derived from a region of chromosome 12 frequently rearranged in soft tissue tumors.

Amplification of cellular oncogenes occurs frequently in several human cancers and is an important mechanism of increased gene expression. Identification of amplified genes in tumor cells has proved to be a useful approach for understanding genetic alterations in cancer. Previous procedures for isolating probes from amplified DNA sequences have relied on tissue culture cells, limiting the range of tumors that can be studied and raising questions of in vitro artifact. We have circumvented these problems by combining in gel renaturation of amplified sequences with the polymerase chain reaction. Using this approach, we have identified and partially cloned a DNA amplification unit from biopsies of human malignant fibrous histiocytoma. This amplification unit is derived from chromosome 12q13-14, a site commonly involved in rearrangements in soft tissue tumors, and contains at least one transcribed region (designated SAS, for sarcoma amplified sequence).