International Journal of Radiation Oncology � Biology � PhysicsS716

(range 4.0-60.4 Gy) in 1.8 Gy fractions (range 1.5-2.0 Gy) most commonly

for Hodgkin’s lymphoma (33%) or ipsilateral breast cancer (28%). His-

tologies of potentially radiation-induced MMs were epithelioid in 89% and

sarcomatoid in 11%, with both sarcomatoid cases occurring among the 5

women previously irradiated for ipsilateral breast cancer. Patients with

potentially radiation-induced MM were more likely to be female than our

remaining 315 patients (56% v 25%, p Z 0.005). The median survival for

patients with potentially radiation-induced MM was 14.9 months from

diagnosis, similar to the remainder of our cohort and comparable to 12.1

months in historical studies of definitive chemotherapy for locally

advanced and metastatic MM.

Conclusions: This study demonstrated the proportion of MM patients with

a prior malignancy was consistent with current cancer rates, but the pro-

portion receiving prior RT to the region of their subsequent MM was

higher than expected. This RT may have acted synergistically with

asbestos exposure and contributed to MM development. This is one of the

largest studies to report a potential association between prior thoracic RT

and MM development and suggests that radiation-induced MM carcino-

genesis can take decades to develop. Survival for radiation-induced MM

does not appear to be significantly different compared with de novo MM.

These results reinforce the importance of highly-conformal RT dose

delivery.

Author Disclosure: A.R. Barsky: None. J.S. Friedberg: None. M. Cull-

igan: None. D.H. Sterman: None. E. Alley: None. L.A. Litzky: None. E.

Glatstein: None. S.M. Hahn: None. K.A. Cengel: None. C.B. Simone:

None.

3283Colorectal Cancer Screening in Cancer Survivors Treated WithRadiation TherapyS. Samiee,1 S. Ahmed,2 K. Hui,2 R. Gryfe,3 A. Pollett,4 M. Cino,5

G. Gingras-Hill,2 A. Ng,6 and D. Hodgson1; 1Department of Radiation

Medicine, Princess Margaret Hospital, Toronto, ON, Canada, 2Clinical

Research Program, Department of Radiation Medicine, Princess Margaret

Hospital, Toronto, ON, Canada, 3Department of Surgery, Mt Sinai

Hospital, ON, Canada, 4Department of Pathology, Mt Sinai Hospital, ON,

Canada, 5Department of Gastroenterology, Toronto Western Hospital,

Toronto, ON, Canada, 6Dana-Farber Cancer Institute, Harvard Medical

School, Boston, MA

Purpose/Objective(s): Due to an increased risk of colorectal cancer

(CRC) among childhood cancer survivors who received abdominal or

pelvic radiation therapy (RT), guidelines recommend that these survivors

should start CRC screening earlier than the general population. However,

there is no evidence suggesting that earlier CRC screening for these sur-

vivors would be effective. We undertook a prospective study to determine

the polyp detection rate among young survivors and compare this to the

20% prevalence rate expected among average risk individuals >50 years

old for whom CRC screening is accepted.

Materials/Methods: Asymptomatic cancer survivors aged 35-49 years

who were treated with abdominal radiation or TBI (at least 12Gy), �10

years prior were eligible. Patients with past medical history of polyps,

Crohn’s disease, ulcerative colitis or any colorectal screening within the

last 5 years were excluded. All patients underwent a full colonoscopic

examination with adequate bowel preparation, and any retrieved polyps

were reviewed by a gastrointestinal pathologist.

Results: Fifty five patients (27 males, 28 females), with a median age of 45

years (43-49), were enrolled. A total of 52 polyps were found in 26 pa-

tients (47.3% of patients; 95% CI Z 31.6%-61.2%). Adenomatous polyps

were found in 19 patients (34%; 95% CI Z 22%-48%). 32% of all polyps

were deemed to be within radiation field (17/52; 95% CI Z 20-47%). 61%

of all polyps were found beyond the ascending colon beyond the reach of a

sigmoidoscope (either in the transverse colon, descending colon or cecum;

32/52; CI Z 47%-74%).

Conclusions: The prevalence of adenomatous colorectal polyps in

abdominal-RT-treated survivors is comparable to or greater than that

described among the general population aged � 50 years, for whom

colorectal cancer (CRC) screening is generally recommended. This pro-

vides indirect support for guidelines recommending the early initiation of

screening, although it is recognized that most polyps occurred outside the

RT field, which complicates interpretation.

Author Disclosure: S. Samiee: None. S. Ahmed: None. K. Hui: None. R.

Gryfe: None. A. Pollett: None. M. Cino: None. G. Gingras-Hill: None.

A. Ng: None. D. Hodgson: None.

3284Long-Term Urinary and Rectal Tolerance in Prostate CancerSurvivors Treated With Definitive Conformal Radiation TherapyM. Knoll, X. Pei, and M.J. Zelefsky; Memorial Sloan-Kettering Cancer

Center, New York, NY

Purpose/Objective(s): To report the incidence and patterns of develop-

ment of urinary and rectal complications in prostate cancer survivors

treated with definitive conformal radiation therapy with long term follow

up exceeding 12 years.

Materials/Methods: 107 patients with biopsy-proven prostate cancer were

treated with definitive RT, with a median follow-up of 15 years (range: 12-

21 years). The median age at last follow-up was 82 years (range 69-94).

Fifty two patients (49%) received neo-adjuvant and concurrent androgen

deprivation therapy in conjunction with RT. The prognostic risk group in

this cohort of patients was as follows: low risk 18% (nZ 19), intermediate

risk 44% (n Z 47 pts), and high risk 38% (n Z 41). Complications were

graded according to the NCI Common Terminology Criteria for Adverse

Events version 3.0. All patients in our prostate database who were treated

with definitive RT were included in this study, as long as they followed up

at our hospital at a minimum follow up of 12 years.

Results: Twenty-one (19.6%) developed hematuria at a median time of 5

years after RT; 20 of these 21 patients presented with 2-3 episodes or less

which subsequently resolved with further follow up. In one patient, he-

maturia was chronic and presented intermittently despite interventions. No

grade 4 hemorrhagic cystitis was observed. Three patients (2.8 %) expe-

rienced grade 2 urinary incontinence (spontaneous, pads indicated), pre-

sented at a median time of 14 year after treatment and resolved at a median

of 1 year. Grade 2 rectal bleeding was observed in 7.5% of this cohort

which presented at a median time of 2 year after treatment and its average

duration before resolution was 1.5 years. One patient had grade 3 rectal

bleeding at 2 years which where were resolved after 6 years from the event.

For rectal incontinence, 7 patients (6.5%) developed grade 1 rectal in-

continence at a median delay of 3.6 yrs and 1 patient (1%) developed grade

2 rectal incontinence at 14 years after RT. One patient had a grade 2

urethral stricture at the 10 year follow up and this was successfully treated.

The median onset of grade 2 and higher rectal and urinary complications

were 2 and 10 years, respectively. Only 14 patients (13.1%) manifested

with a urinary or rectal complication after 10 years of follow up (only 4 of

them were grade 2 events) and these were generally transient.

Conclusions: Excellent tolerance of conformal radiation therapy is

observed beyond 10 years from therapy. Manifestations of complications

beyond 10 years are uncommon and such events in this cohort were

generally transient. These data dispel the notion that significant compli-

cations develop beyond 10 years after radiation therapy.

Author Disclosure: M. Knoll: None. X. Pei: None. M.J. Zelefsky: None.

3285Lymphedema: Is It Associated With Lymph-Node Involvement inEndometrial Cancer?D. Mitra, N.C. Cimbak, L.J. Lee, and A.N. Viswanathan; Dana-Farber/

Brigham and Women’s Cancer Center, Boston, MA

Purpose/Objective(s): To investigate which factors influence the likeli-

hood of lymphedema in patients with endometrial cancer who receive

adjuvant radiation therapy (RT).