radiation for gastric cancer

Stomach (Gastric) CancerRobert Miller MD

www.aboutcancer.com

Gastric Cancer

Role of Radiation

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.

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.

Smoking Cessationsmoking increases the risk of stomach cancer by 60% in men and 20% in women, and cessation lowers the risk

H. Pylori infection eradicationtreatment of this infection will lower the risk of gastric cancer by 35 to 39%

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

Age Distribution

< 20 29-34 35-44 45-54 55-64 65-74 75-84 85+0

5

10

15

20

25

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

Symptoms of Gastric CancerSymptom PercentWeight loss 62%Abdominal pain 52%Nausea 34%Dysphagia 26%Melena 20%Early satiety 18%Ulcer type pain 17%

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)

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

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

Layers of the Stomach

Gastric pits

Gastric glands

Blood vessels

Oblique muscle

Circular muscle

Longit. muscle

Connectivetissue

Mucosa

Serosa

Submucosa

Muscularis

Mucosa

Submucosa

Muscularis

Serosa

Layers of the Stomach

T (tumor) Stage

Stomach and Regional Lymph Nodes

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

N (lymph node) Stage

TNM Stage

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%

Primary Treatment of Gastric Cancer is Surgery

Is there a role for radiation in the treatment of gastric cancer?

Conventional radiation IMRT radiation

High risk of a local relapse after surgery

Site of a local relapse after surgery

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%)

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

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 * PhysicsVolume 63, Issue 5 , Pages 1279-1285, 1 December 2005

5yr RFSCRT (+) 54.5%CRT (-) 47.9%

0 20 40 60 80 100 120 Months

Relapse Free Survival after Surgery for Gastric Cancer with or without CRT (chemo-

radiation)

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

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

NCCN.org

Surgery or PreOp Chemo or Chemo-RT then Surgery

Surgery or PostOp Chemo or Chemo-RT then Surgery


R0 = complete resection with negative margins


High Risk Features: poor diff or high grade, lymphovascular or perineural invasion or age <50y


R1 = resection with + microscopic marginsR2 = resection with macroscopic (visible) cancer left behind

Radiation Technique for Gastric Cancer

Radiation Guidelines

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.

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

Stomach (Gastric) Cancer

role of radiation

Robert Miller MDwww.aboutcancer.com

radiation for gastric cancer

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