The role of radiation in treating gastric or stomach cancer

1. Stomach (Gastric) Cancer
Robert Miller MD
www.aboutcancer.com

2. Gastric
Cancer
Role of
Radiation

3. Men Women
New Cases 13,230 8,370
Death 6,740 4,250
Stomach Cancer in 2013
Stomach cancer accounted for only 1.3% of all new cancers and
1.9% of cancer deaths,
The lifetime risk of ever getting stomach cancer is 1% for men and
0.7% for women. Based on rates from 2008-2010, 0.86% of men
and women born today will be diagnosed with cancer of the
stomach at some time during their lifetime.

4. Risk Factors In the United States, gastric cancer ranks 14th in
incidence among the major types of cancer malignancies. While the precise
etiology is unknown, acknowledged risk factors for gastric cancer include
the following:
Helicobacter pylori gastric infection.
Advanced age.
Male gender.
Diet low in fruits and vegetables.
Diet high in salted, smoked, or preserved foods.
Chronic atrophic gastritis.
Intestinal metaplasia.
Pernicious anemia.
Gastric adenomatous polyps.
Family history of gastric cancer.
Cigarette smoking.
Menetrier disease (giant hypertrophic gastritis).
Familial adenomatous polyposis.

5. Smoking Cessation
smoking increases the risk of stomach cancer by
60% in men and 20% in women, and cessation
lowers the risk
H. Pylori infection eradication
treatment of this infection will lower the risk of gastric
cancer by 35 to 39%

6. Cancer Men Women
All Cancers 66 65
Stomach 69 72
Median Age at Diagnosis in 2005-09
From 2006-2010, the median age at diagnosis for cancer of the
stomach was 69 years of age

7. Age Distribution
0
5
10
15
20
25
< 20 29-34 35-44 45-54 55-64 65-74 75-84 85+

10. 1975-77 1987-89 2002-8
All
Cancers
49% 56% 68%
Stomach 15% 20% 28%
Trends in 5-Year Relative Survival Rates(%)
by Year of Diagnosis, United States, 1975 to
2008

11. Symptoms of Gastric Cancer
Symptom Percent
Weight loss 62%
Abdominal pain 52%
Nausea 34%
Dysphagia 26%
Melena 20%
Early satiety 18%
Ulcer type pain 17%

13. Pathology Report
• Histology (usually adenocarcinoma, intestinal
or diffuse type)
• Depth of invasion (resection the completeness of
the resection so the surgical margins and the lymph
nodes involved)
• Grade of the cancer
• Other risk factors (lymphovascular or perineural
invasion)

14. Stage at
Diagnosis
Distribution 5 Year
Survival
Localized 25% 63%
Regional 39% 28%
Distant 34% 4%
Stage Distribution and 5-year Relative
Survival for 2003-2009

15. Inner layer or lining (mucosa): Juices made
by glands in the inner layer help digest food.
Most stomach cancers begin in this layer.
Submucosa: This is the support tissue for the
inner layer.
Muscle layer: Muscles in this layer contract to
mix and mash the food.
Sub serosa: This is the support tissue for the
outer layer.
Outer layer (serosa): The outer layer covers the
stomach. It holds the stomach in place.
The wall of the stomach has five layers

16. Layers of the Stomach
Gastric pits
Gastric
glands
Blood vessels
Oblique muscle
Circular muscle
Longit. muscle
Connective
tissue
Mucosa
Serosa
Submucosa
Muscularis

17. Mucosa
Submucosa
Muscularis
Serosa
Layers of the Stomach

18. T (tumor) Stage

19. Stomach and Regional Lymph Nodes

20. Gastric cancer lymph node stations.
Lymph node stations surrounding the
stomach: 1, right cardial nodes; 2, left
cardial nodes; 3, nodes along the lesser
curvature; 4, nodes along the greater
curvature; 5, suprapyloric nodes; 6,
infrapyloric nodes; 7, nodes along the
left gastric artery; 8, nodes along the
common hepatic artery; 9, nodes
around the celiac axis; 10, nodes at the
splenic hilus; 11, nodes along the
splenic artery; 12, nodes in the
hepatoduodenal ligament; 13, nodes at
the posterior aspect of the pancreas
head; 14, nodes at the root of the
mesentery; 15, nodes in the mesocolon
of the transverse colon; 16, para-aortic
nodes.
Stomach and Regional Lymph Nodes

21. N (lymph node) Stage

22. TNM Stage

23. 5 Year Survival by Stage
IA 70.8%
IB 57.4%
IIA 45.5%
IIB 32.8%
IIIA 19.8%
IIIB 14.0%
IIIC 9.2%
IV 4.0%

24. Primary Treatment of Gastric Cancer is Surgery

25. Is there a role for radiation in the
treatment of gastric cancer?
Conventional radiation IMRT radiation

26. High risk of a local relapse after
surgery

27. Site of a local relapse after
surgery

28. Post Operative or PreOp
Radiation for Gastric Cancer
Local relapse (PostOp Trial, British Stomach Cancer Group,
Lancet. 1994 May 28;343(8909):1309-12)
surgery alone (27%)
surgery plus radiation (10%)
surgery plus chemotherapy (19%)
Survival (PreOp Trial by Zhang Int J Radiat Oncol Biol Phys. 1998 Dec
1;42(5):929-34)
surgery alone (20%)
radiation then surgery (30%)

29. Updated Analysis of SWOG-Directed Intergroup Study 0116: A
Phase III Trial of Adjuvant Radiochemotherapy Versus Observation
After Curative Gastric Cancer Resection
JCO July 1, 2012 vol. 30 no. 192327-2333

30. Relapse-free survival of patients treated with adjuvant
chemoradiation as compared with untreated control patients. CRT =
chemoradiotherapy; RFS = relapse free survival.
International Journal of Radiation Oncology * Biology * Physics
Volume 63, Issue 5 , Pages 1279-1285, 1 December 2005
5yr RFS
CRT (+) 54.5%
CRT (-) 47.9%
0 20 40 60 80 100 120
Months

31. Relapse Free Survival after Surgery for
Gastric Cancer with or without CRT (chemo-
radiation)

32. Impact of adjuvant radiation therapy (RT)
on overall survival (OS)
Hazard ratios (HR) for each trial are represented by squares, the size of
each square represents the weight of that trial in the meta-analysis, and
the horizontal line crossing the square represents the 95% confidence
interval. Diamonds represent the estimated overall effect based on meta-
analysis. *Included intraoperative radiation therapy.
favors radiation favors no radiation

33. Survival after radiotherapy in
gastric cancer: systematic
review and meta-analysis.
Radiotherapy had a significant impact on 5-year survival. Using an intent to
treat (ITT) and a Per Protocol (PP) analysis, the overall 5-year RR was
1.26 and 1.31 respectively. (Survival improved by 26 to 31%)
This meta-analysis showed a statistically significant 5-year survival benefit
with the addition of radiotherapy in patients with resectable gastric cancer.
Radiother Oncol. 2009 Aug;92(2):176-83

34. NCCN.org

35. Surgery or PreOp Chemo or Chemo-RT
then Surgery

36. Surgery or PreOp Chemo or Chemo-RT
then Surgery

37. Surgery or PreOp Chemo or Chemo-RT
then Surgery

38. Surgery or PreOp Chemo or Chemo-RT
then Surgery

39. Surgery or PostOp Chemo or Chemo-RT
then Surgery

40. Surgery or PostOp Chemo or Chemo-RT
then Surgery
R0 = complete resection with negative margins

41. Surgery or PostOp Chemo or Chemo-RT
then Surgery
High Risk Features: poor diff or high grade, lymphovascular or perineural
invasion or age <50y

42. Surgery or PostOp Chemo or Chemo-RT
then Surgery
R1 = resection with + microscopic margins
R2 = resection with macroscopic (visible) cancer left behind

43. Radiation Technique for
Gastric Cancer

44. Radiation Guidelines

45. Clinical benefit of palliative radiation therapy in advanced gastric
cancer.
Department of Radiation Oncology, The University of Texas M.D. Anderson
Cancer Center, Houston, Texas 77030, USA.
The rates of control for bleeding, (70%) dysphagia/obstruction (81%)
and pain (86%)
These symptoms were controlled without additional interventions for a
median of 70%, 81%, and 49% of the patient's remaining life,
respectively.
Patients receiving CRT had a trend towards better median overall
survival than those receiving RT alone (6.7 vs. 2.4 months,).
Lower radiation dose (<41 Gy predicted for poorer local control (6-month
local control 70% vs. 100%,
Acta Oncol. 2008;47(3):421-7.

46. The role of palliative radiation therapy in symptomatic locally
advanced gastric cancer.
Department of Radiation Oncology, The Cancer Institute, National
University Hospital, Singapore.
The majority of patients received 30 Gy/10 fractions . Median survival was
145 days, actuarial 12-month survival 8%.
A total of 54.3% with bleeding responded (median duration of response of
140 days), 25% with obstruction responded (median duration of response
of 102 days), and 25% with pain responded (median duration of response
of 105 days)
Int J Radiat Oncol Biol Phys. 2007 Feb 1;67(2):385-8. Epub 2006 Nov
21

47. Stomach (Gastric)
Cancer
role of radiation
Robert Miller MD
www.aboutcancer.com