There are several unresolved problems in the treatment of low grade gastric lymphoma, страница 3

Relapse should be proven histologically wherever possible, and the site of relapse documented on the follow-up form.

LI Relapse after initial randomisation to observation alone. It is advisable to restage the patient. If H. pylori infection is present this should be treated. If a complete response is obtained a further period of observation can be undertaken. We recommend that incomplete response is treated by chlorambucil.

L2 Relapse or progression after initial randomisation to chlorambucil. It is advisable to restage the patient. Treatment is at the discretion of the clinician since the clinical circumstances vary. If H. pylori infection is present this should be treated. If a complete response is obtained a period of observation can be undertaken. Incomplete responses can be treated with further cytotoxic therapy with chlorambucil, but consideration should be given to more intensive chemotherapy (e.g. CHOP)/ or to local surgical or radiation treatment depending on the clinical circumstances.

15. Endpoints and statistical considerations

The end point is recurrence rate. It is unlikely that any survival difference will be large enough to be detectable in a study of a size which can realistically be expected.

If the endoscopic relapse rate in the patients treated for H. pylori infection without chlorambucil is 40% at 5 years, 173 patients would be required to demonstrate a reduction to 20% with 5% significance level and 80% power. The anticipated recruitment will therefore be 200 patients.

16. Interim analysis

A formal analysis will be made after recruitment of the first 50 patients to determine the feasibility of the study and any early major difference in relapse rate in the randomised arms. Thereafter analyses will be made annually. A Data Monitoring Committee will be established to undertake independent formal review.

17. Ethical considerations

Before entering patients into the study, clinicians must ensure that the protocol has received clearance from their local Ethical Committee. The patient's consent to participate in the study should be obained after a full explanation has been given of the treatment options, including the conventional and generally accepted methods of treatment, and the manner of treatment allocation.

The right of a patient to refuse to participate without giving reasons must be respected. After the patient has entered the trial the clinican must remain free to give alternative treatment to that specified in the protocol at any stage if it is felt to be in the patient's best interests. The reasons for giving such alternative treatment must be recorded and the patient should remain within the study for the purposes of follow-up and data analysis according to the treatment option to which he/she had been allocated. Similarly, the patient must remain free to withdraw at any time from protocol treatment without giving reasons and without prejudicing his/her further treatment.

18. References

Isaacson PG and Spencer J (1990) Malignant lymphoma of mucosa associated lymphoid tissue. Histopathology 11:445-462.

Shepherd FA, Evans WK, Kutas G, et al (1988) Chemotherapy following surgery for stages IE and HE non-Hodgkin's lymphoma of the gastrointestinal tract. J Clin Oncol, 6:253-260.

Shimm DS/ Dosoretz DE/ Anderson T, et al (1983) Primary gastric lymphoma:

an analysis with emphasis on prognostic factors and radiation therapy. Cancer


Wotherspoon AC, Ortiz-Hildago C, Falzon MF, Isaacson PG (1991) Helicobacter pylori-associated gastritis and primary B-cell gastric lymphoma. Lancet 338:1175-1176.

Wotherspoon AC, Doglioni C, Isaacson PG (1992) Low grade gastric B-cell lymphoma of mucosa-assocaited lymphoid tissue (MALT): a multifocal disease. Histopathology 20:29-34.

Wotherspoon AC, Doglioni C, Diss TC et al (1993) Regression of primary low-grade B-cell gastric lymphoma of mucosa-associated lymphoid tissue type after eradication of Helicobacter pylori. Lancet 342:575-577.


Registration form Follow up after H.Pylori treatment

Follow up after endoscopy 6 monthly for 2 years Then yearly

Follow up after chlorambucil Follow up after observation

Proposed staging for gastro-intestinal lymphoma

Stage 1      No serosal penetration.

Single site or multiple non-contiguous primary

2  Extending into abdomen with nodal involvement

2a local nodes involved 2b distal nodes

2в  Penetration to adjacent structures 4      Disseminated extra-nodal disease