ESTRO 38 Abstract book

S430 ESTRO 38

Medical Oncology, Aviano, Italy ; 9 Centro di Riferimento Oncologico CRO - IRCCS- Aviano-Italy, Cancer Epidemiology, Aviano, Italy ; 10 Centro di Riferimento Oncologico CRO - IRCCS- Aviano-Italy, Surgical Oncology, Aviano, Italy Purpose or Objective Organ preservation strategy with local excision (LE) or watch and wait (W-W) in selected patients (pts) with locally advanced rectal cancer (LARC) who achieve a major (mCR) or complete clinical response (cCR) after preoperative chemoradiotherapy (CRT) may offer an opportunity to avoid major surgery and its effects on anorectal, sexual and urinary functions and quality of life. We report the long term outcome of pts undergoing pre- operative CRT and LE at our Istitution Material and Methods Between January 1998 and July 2017 LE was proposed to pts as an alternative to TME after CRT when mCR or cCR were assessed at DRE, endoscopy with biopsy and MRI. CT- PET was used since 2002 in staging and restaging to characterize also metabolic response. LE was performed using either the traditional transanal approach or Transanal Micro Invasive surgery (TAMIS). Pathologic response was defined as pT stage and Mandard Tumor Regression Grade (TRG). Pts who achieved TRG1 or TRG2 were going to follow-up, whereas was planned for pT1-3, TRG3-5. Long term outcome was assessed by Log-Rank test in terms of 5 and 10yrs OS, DFS and local DFS (LDFS) and Colostomy Free Survival (CFS). Results Seventy-four pts (M/F: 47/27 ; median age 66 yrs, range 25-85) underwent to LE. Clinical stage at presentation was I in 10 pts, II in 39 and III in 25.Median distance from anal verge was 3.5 cm (range 2-8 cm). Radiotherapy (RT) consisted of 45-50.4 Gy in 25-28 frs in 50 pts and 45-54 Gy in 25 frs (IMRT-SIB) in 24 pts. Concomitant 5-FU or Capecitabine based chemotherapy was associated to RT in all pts. Pathologic T stage after LE was available for 70 pts; 4 pts with cCR entered in a W-W program. pT0 was achieved in 39 pts (56%), pT1-3 in 31 (44%). Overall 50 pts (71%) achieved TRG1 or TRG2 and 20 TRG3-5. Twelve of 20 TRG 3-5pts underwent to TME while 8 pts refused radical surgery. With a minimum follow up of 2 yrs (range 2-20yrs), the 5 and 10-yrs LDFS, DFS and OS in the overall 74 pts were 88.1% and 88.1%, 77.3% and 71.5%, and 88.2% and 74.4%, respectively. For the 43 T0 pts, including 39 pT0 and 4 cCR in W-W program, the 5 and 10-yrs LDFS, DFS and OS were 94.7% and 94.7%, 84% and 73.5%, and 91.6% and 73.2%, respectively. No significant difference of outcome were found between TRG1-2 and TRG3-5 pts, most receiving radical TME. At the same median follow up, 17 pts (24%) needed colostomy, 7 (14%) in TRG1-2 group and 10 (50%) in TRG3-5 respectively. The 10yrs CFS was 87.8% in TRG1-2 group and 52.7% in TRG3-5 and it was significantly different (p=0.001) in these two subset of pts. No major complication were reported; 3 pT0 pts needed colostomy for fecal incontinence (2pts) or rectal stenosis (1pt) after LE. Conclusion Organ preservation with LE after CRT appears safe with favourable long-term outcome for selected LARC patients who achieve mCR or cCR. TME performed after LE don’t get worse outcome in TRG3-5 pts. LE confirms a valid approach in organ preservation to improve quality of life in these pts.

1 MacKay Memorial Hospital, Radiation Oncology, Taipei, Taiwan ; 2 Changhua Christian Hospital, Radiation Oncology, Changhua, Taiwan ; 3 MacKay Memorial Hospital, Obstetrics and Gynecology, Taipei, Taiwan Purpose or Objective Treatment-related toxicities and decreased levels of patient performance during cancer therapy might contribute to body composition changes and thereby impact outcomes. However, the effect of longitudinal body composition changes on outcomes in patients with advanced endometrial cancer is unknown. This study investigated the association between body composition changes during staging surgery and adjuvant chemoradiotherapy and outcomes in patients with stage III Pre- and post-treatment computed tomographic (CT) images of 131 patients with stage III endometrial cancer who were treated at 2 tertiary centers between 2008 and 2016 were analyzed. The skeletal muscle index (SMI), skeletal muscle radiodensity (SMD), and total adipose tissue index (TATI) were measured from 2 sets of CT images obtained at the level of the L3 vertebra. Patients with a reduction or increase in the SMD of ≥5.0% were classified as having ‘SMD loss’ or ‘SMD gain’, respectively. Predictors of overall survival (OS) and progression-free survival (PFS) were identified using Cox regression models. Results The median follow-up was 50.6 (range, 12.1–117.0) months. Overall, patients lost an average of 2.1% per 210 days (95% CI: -4.0 to -0.2; p = 0.03) of SMD and 0.2% per 210 days (95% CI: -1.5 to 1.0; p = 0.70) of SMI. Patients gained an average of 3.2% per 210 days (95% CI: -0.2 to 6.7; p = 0.07) of TATI. Changes in SMD did not correlate with weight change (Spearman’s ρ for SMD, -0.13; p = 0.13). Changes in SMI and TATI positively correlated with weight change (Spearman’s ρ for SMI, 0.20; p = 0.02; ρ for TATI, 0.40; p = 0.001). The 5-year OS for patients with SMD loss, stable SMD, and SMD gain were 59.7%, 94.0%, ad 90.5%, respectively ( p < 0.001; Figure 1); the corresponding PFS were 55.9%, 92.8%, and 85.7%, respectively ( p < 0.001; Figure 1). On multivariable analysis, an SMD loss ≥5.0%/210 days of treatment was independently associated with poorer OS (hazard ratio: 10.20, 95% confidence interval: 2.24–46.42; p = 0.003) and PFS (hazard ratio: 7.36, 95% confidence interval: 2.09– 25.95; p = 0.002). Pretreatment myosteatosis and sarcopenia, as well as changes in SMI and TATI during treatment, were not associated with survival. The pretreatment skeletal muscle gauge was associated with treatment modifications such as delays, dose reductions, and discontinuation of chemotherapy. endometrial cancer. Material and Methods

Poster: Clinical track: Gynaecological (endometrium, cervix, vagina, vulva)

PO-0822 Muscle density loss during cancer therapy for advanced endometrial cancer portends poor survival J. Lee 1 , J. Lin 2 , C. Chang 3 , M. Wu 1 , Y. Chen 1