Philip P. Connell

Stereotactic body radiotherapy for multisite extracranial oligometastases: final report of a dose escalation trial in patients with 1 to 5 sites of metastatic disease.

A subset of patients with metastatic cancer in limited organs may benefit from metastasis‐directed therapy. The authors investigated whether patients with limited metastases could be safely treated with metastasis‐directed radiotherapy.

Significant pelvic recurrence in high-risk pathologic stage I--IV endometrial carcinoma patients after adjuvant chemotherapy alone: implications for adjuvant radiation therapy.

OBJECTIVE To evaluate the risk of pelvic recurrence (PVR) in high-risk pathologic Stage I--IV endometrial carcinoma patients after adjuvant chemotherapy alone. METHODS Between 1992 and 1998, 43 high-risk endometrial cancer patients received adjuvant chemotherapy. All patients underwent primary surgery consisting of total abdominal hysterectomy and bilateral salpingo-oophorectomy. No patients received preoperative radiation therapy (RT). Regional lymph nodes and peritoneal cytology were sampled in 62.8% and 83.7% of cases, respectively. Most patients had Stage III--IV disease (83.7%) or unfavorable histology tumors (74.4%). None had evidence of extra-abdominal disease. All patients received 4-6 cycles of chemotherapy as the sole adjuvant therapy, consisting primarily of cisplatin and doxorubicin. Recurrent disease sites were divided into pelvic (vaginal, nonvaginal) and extrapelvic (para-aortic, upper abdomen, liver, and extra-abdominal). Median follow-up was 27 months (range, 2--96 months). RESULTS Twenty-nine women (67.4%) relapsed. Seventeen (39.5%) recurred in the pelvis and 23 (55.5%) in extrapelvic sites. The 3-year actuarial PVR rate was 46.5%. The most significant factors correlated with PVR were cervical involvement (CI) (p = 0.01) and adnexal (p = 0.05) involvement. Of the 17 women who developed a PVR, 8 relapsed in the vagina, 3 in the nonvaginal pelvis, and 6 in both. The 3-year vaginal and nonvaginal PVR rates were 37.8% and 26%, respectively. The most significant factor correlated with vaginal PVR was CI (p = 0.0007). Deep myometrial invasion (p = 0.02) and lymph nodal involvement (p = 0.03) were both correlated with nonvaginal PVR. Nine of the 29 relapsed patients (31%) developed PVR as their only (6) or first site (3) of recurrence. Factors associated with a higher rate of PVR (as the first or only site) were CI and Stage I--II disease. CONCLUSIONS PVR is common in high-risk pathologic Stage I-IV endometrial cancer patients after adjuvant chemotherapy alone. These results support the continued use of locoregional RT in patients undergoing adjuvant chemotherapy. Further studies are needed to test the addition of chemotherapy to locoregional RT.

RI-1: a chemical inhibitor of RAD51 that disrupts homologous recombination in human cells

Homologous recombination serves multiple roles in DNA repair that are essential for maintaining genomic stability. We here describe RI-1, a small molecule that inhibits the central recombination protein RAD51. RI-1 specifically reduces gene conversion in human cells while stimulating single strand annealing. RI-1 binds covalently to the surface of RAD51 protein at cysteine 319 that likely destabilizes an interface used by RAD51 monomers to oligomerize into filaments on DNA. Correspondingly, the molecule inhibits the formation of subnuclear RAD51 foci in cells following DNA damage, while leaving replication protein A focus formation unaffected. Finally, it potentiates the lethal effects of a DNA cross-linking drug in human cells. Given that this inhibitory activity is seen in multiple human tumor cell lines, RI-1 holds promise as an oncologic drug. Furthermore, RI-1 represents a unique tool to dissect the network of reaction pathways that contribute to DNA repair in cells.

A Phase I Study of Pemetrexed, Carboplatin, and Concurrent Radiotherapy in Patients with Locally Advanced or Metastatic Non–Small Cell Lung or Esophageal Cancer

Purpose: The primary objective of this phase I study was to determine the maximum tolerated dose for pemetrexed, alone and in combination with carboplatin, with concurrent radiotherapy. Experimental Design: Patients with locally advanced or metastatic non–small cell lung cancer (NSCLC) or esophageal cancer were treated every 21 days for two cycles. Regimen 1 was pemetrexed (200-600 mg/m2); regimen 2 was pemetrexed (500 mg/m2) with escalating carboplatin doses (AUC = 4-6). Both regimens included concurrent radiation (40-66 Gy; palliative-intent doses were lower). Results: Thirty patients (18 locally advanced and 12 metastatic with dominant local symptoms) were enrolled, with an Eastern Cooperative Oncology Group performance status of 0/1/2 (n = 8/21/1). All dose levels were tolerable for regimen 1 (n = 18: 15 NSCLC and 3 esophageal cancers) and regimen 2 (n = 12: all NSCLC). In regimen 1, one dose-limiting toxicity (grade 4 esophagitis/anorexia) occurred (500 mg/m2). Grade 3 neutropenia (3 of 18 patients) was the main hematologic toxicity. In regimen 2, one dose-limiting toxicity (grade 3 esophagitis) occurred (500 mg/m2; AUC = 6); grade 3/4 leukopenia (4 of 12 patients) was the main hematologic toxicity. Four complete responses (2 pathology proven) and eight partial responses were observed. When systemically active chemotherapy doses were reached, further dose escalation was discontinued, and a phase II dose-range was established (pemetrexed 500 mg/m2 and carboplatin AUC = 5-6). Conclusions: The combination of pemetrexed (500 mg/m2) and carboplatin (AUC = 5 or 6) with concurrent radiation is well tolerated, allows for the administration of systemically active chemotherapy doses, and shows signs of activity. To further determine efficacy, safety profile, and optimal dosing, the Cancer and Leukemia Group B study 30407 is currently evaluating this regimen in patients with unresectable stage III NSCLC.

Advances in Radiotherapy and Implications for the Next Century: A Historical Perspective

The use of ionizing radiation for the treatment of cancer dates back to the late 19th century, remarkably soon after Roentgen described X-rays in 1895 and the use of brachytherapy after Marie and Pierre Curie discovered radium in 1898. These initial efforts stimulated a revolution of conceptual and

Characteristics and Outcome of Endometrial Carcinoma Patients Age 45 Years and Younger

Recent reports have suggested that the pathologic features of young patients with endometrial cancer are less favorable than previously thought. We retrospectively reviewed the characteristics and outcome of young patients with endometrial cancer at our institution. A total of 457 surgically staged patients were divided in 2 groups: Group A (age ≤45 years, n = 41) and B (age >45, n = 416). Groups A and B had a similar distribution of tumor stage, grade, histology, lymphovascular invasion, synchronous ovarian primaries, and positive cytology. Although group A tumors had less myometrial invasion (MI) (p = 0.004) and were lower grade (p = 0.06), a trend to more frequent nodal involvement was seen in group A women (p = 0.09). Adverse pathologic features, in particular deep MI, were more common in group A patients older than age 40. Group A patients had a disease-free (p = 0.56) and cause-specific (p = 0.26) survival that was similar to that of group B patients. Young patients with endometrial cancer have a distribution of most pathologic features and equivalent outcome similar to that of older women. However, adverse features are not equally distributed in young women. A discordance may also exist between MI, grade, and nodal involvement.

Hypofractionated Image-Guided Radiation Therapy for Patients with Limited Volume Metastatic Non-small Cell Lung Cancer

Introduction: Outcomes data treating patients with oligometastatic (⩽5 metastases) non-small cell lung carcinoma (NSCLC) with hypofractionated image-guided radiotherapy (HIGRT) are limited. Methods: Consecutive oligometastatic NSCLC patients were reviewed from a prospective database. Patients were included if all active diseases were treated with HIGRT. Lesions that had received prior radiation or had radiographic/metabolic resolution after chemotherapy were not treated with HIGRT. Local control of all treated lesions, distant control, progression-free survival (PFS), overall survival (OS), and control of individual lesions (LeC) were calculated. Results: Twenty-five patients with median of 2 treated oligometastatic lesions were included. Median follow-up was 14 months. Median age was 66 years. Nineteen patients received systemic therapy before HIGRT and 11 had progressive disease after their most recent systemic therapy before HIGRT. Median OS and PFS were 22.7 and 7.6 months. The 18 months local control, distant control, OS, and PFS were 66.1%, 31.7%, 52.9%, and 28.0%. Greater than two sites treated with HIGRT, nonadenocarcinoma histology, prior systemic therapy, and progression after systemic therapy were associated with worse PFS. Sixty-two individual lesions of median size 2.7 cm were treated. For extracranial lesions, median total and fraction dose were 50 and 5 Gy. Median standard equivalent dose in 2 Gy fractions for extracranial lesions was 64.6 Gy yielding 18 months LeC of 70.7%. Standard equivalent dose ≥64.6 Gy increased LeC (p = 0.04). Two patients experienced grade 3 toxicity. Conclusions: HIGRT for oligometastatic NSCLC provides durable LeC and may provide long-term PFS in some patients. Future HIGRT studies should optimize patient selection and integration with systemic therapy.

New Paradigms and Future Challenges in Radiation Oncology: An Update of Biological Targets and Technology

The future of radiation therapy lies in both technical and biological advances. Radiation oncology exploits the biological interaction of radiation within tissue to promote tumor death while minimizing damage to surrounding normal tissue. The clinical delivery of radiation relies on principles of radiation physics that define how radiation energy is deposited in the body, as well as technology that facilitates accurate tumor targeting. This review will summarize the current landscape of recent biological and technological advances in radiation oncology, describe the challenges that exist, and offer potential avenues for improvement.

A chemical compound that stimulates the human homologous recombination protein RAD51

RAD51 and other members of the RecA family of strand exchange proteins assemble on ssDNA to form presynaptic filaments, which carry out the central steps of homologous recombination. A microplate-based assay was developed for high-throughput measurement of hRAD51 filament formation on ssDNA. With this method, a 10,000 compound library was screened, leading to the identification of a small molecule (RS-1) that enhances hRAD51 binding in a wide range of biochemical conditions. Salt titration experiments showed that RS-1 can enhance filament stability. Ultrastructural analysis of filaments formed on ssDNA showed that RS-1 can increase both protein–DNA complex lengths and the pitch of helical filament turns. RS-1 stimulated hRAD51-mediated homologous strand assimilation (D-loop) activity by at least 5- to 11-fold, depending on the condition. This D-loop stimulation occurred even in the presence of Ca2+ or adenylyl-imidodiphosphate, indicating that the mechanism of stimulation was distinct from that conferred by Ca2+ and/or inhibition of ATPase. No D-loop activity was observed in the absence of a nucleotide triphosphate cofactor, indicating that the compound does not substitute for this requirement. These results indicate that RS-1 enhances the homologous recombination activity of hRAD51 by promoting the formation of active presynaptic filaments. Cell survival assays in normal neonatal human dermal fibroblasts demonstrated that RS-1 promotes a dose-dependent resistance to the cross-linking chemotherapeutic drug cisplatin. Given that RAD51-dependent recombination is a major determinant of cisplatin resistance, RS-1 seems to function in vivo to stimulate homologous recombination repair proficiency. RS-1 has many potential applications in both research and medical settings.

Surgery and postoperative radiation therapy in FIGO stage IIIC endometrial carcinoma

OBJECTIVE To determine the outcome, pattern(s) of failure, and optimal treatment volume in Stage IIIC endometrial carcinoma patients treated with surgery and postoperative radiation therapy (RT). METHODS Between 1983 and 1998, 30 Stage IIIC endometrial carcinoma patients were treated with primary surgery and postoperative RT at the University of Chicago. All underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, sampling of pelvic lymph nodes (PLN), and peritoneal cytology. All were noted to have PLN involvement. Para-aortic lymph nodes (PALN) were sampled in 26 cases, and were positive in 14 cases (54%). Twenty women received whole-pelvic RT (WPRT) and 10 (WPRT), plus paraortic RT (extended-field RT, EFRT). One EFRT patient also underwent concomitant whole-abdominal RT (WART). Adjuvant vaginal brachytherapy (VB) was delivered in 10, chemotherapy in 5, and hormonal therapy in 7 patients. RESULTS At a median follow-up of 32 months, the actuarial 5-year disease-free and cause-specific survivals of the entire group were 33.9% and 55.8%, respectively. Overall, 16 women (53%) relapsed. Sites of failure included the pelvis (23%), abdomen (13%), PALN (13%), and distant (40%). Of the 7 pelvic failures, 4 were vaginal (3 vaginal only). Patients treated with VB had a trend to a lower vaginal recurrence rate (0/10 vs. 4/20, p = 0.12) than those not receiving VB. All 4 PALN failures were in women treated with WPRT (2 negative, 1 unsampled, and 1 positive PALN). None of the 10 EFRT patients (2 negative, 8 positive PALN) recurred in the PALN. No patient developed an isolated abdominal recurrence. Two patients developed significant RT sequelae: chronic diarrhea in 1 patient treated with WPRT and VB, and small bowel obstruction in 1 patient treated with EFRT. CONCLUSION FIGO Stage IIIC disease comprises a small percentage of endometrial carcinoma patients but carries a poor prognosis. Our failure pattern suggests that the optimal adjuvant RT volume is EFRT, even in women with negative PALN sampling. VB should also be administered to improve local control. The low rate of abdominal recurrence does not support the routine use of WART in these women. Given the predominance of failure in distant sites, attention should be focused on the development of systemic chemotherapy protocols.