Trial Information

Prospective Randomized Trial: Curettage Versus Excision in Nodular and Superficial Basal Cell Carcinomas

1. First presentation of a patient with clinical or histopathological diagnosis of BCC

2. Study patient number, first and surname, date of birth and gender are listed in a
distinct file.

3. Informed consent

4. Whole body screening for skin cancer

5. In- or exclusion of the patient. If the patient is excluded, no more data are obtained.

6. Recording of the following features in an electronic file:

1. Number of BCCs

2. Anatomic location

- Lip

- Eyelid

- Ear

- Nose

- Other parts of the face

- Scalp or neck

- Trunk

- Arm, hand, or shoulder

- Leg, foot, or hip

3. Position

- Ventral or dorsal. If the tumor is located at the lateral margin of ventral
and dorsal, it is considered ventral.

- Right, left, midline

- Distinct BCCs are numbered. To ensure future distinction of different tumors,
numbering starts with the most up-right-ventral tumor and ends with the most
down-left-dorsal one. Numbering continues with BCCs that appear later during
the period of recruitment.

4. Diameter in mm

7. In- or exclusion of the tumor

8. Photographs of the included BCCs

9. Randomization is performed by the Department of Biostatistics (distance to the
Department of Dermatology = 1.7 km) with envelopes containing the assigned study arm.
The study physician calls one of four staff members of the Department of Biostatistics
and asks for randomization. The envelopes are not opened unless the electronic data
file is completed by the study physician.

10. Disinfection

11. Local anesthesia

12. Surgery

13. Dressing

14. If histopathology discovers another BCC type than nodular or superficial or even
another tumor than BCC, then the tumor is excluded.

15. Follow-up visit 3 and 6 months (+/- 30 days) after the operation. In BCCs that had to
be operated in >1 step, the day of the follow-up visit refers to the initial operation.

16. In case of clinical suspicion of recurrence of BCC a punch biopsy is taken. If the
biopsy confirms recurrence, the endpoint is achieved.

17. If BCCs must be added to a patient during the recruitment period, follow-up visits
always refer to the latest BCC.

18. If the patient visits our department not within the defined follow-up period, the
appointment is not recorded (except confirmation of recurrence).

19. Patients who provide no feedback receive phone calls.

20. If a patient or a private practitioner suspect a recurrence of BCC beyond a defined
follow-up period, of course, the patient is invited as early as possible to our
department, where a biopsy will be taken.

21. The patient receives a letter containing a list of the BCCs treated within the study.
The private practitioner is to be visited with the list after 12, 24, and 36 months
(+/- 30 days) referring to the last operation within the recruitment period. The letter
contains a questionnaire about scar size and suspicion of recurrence of BCC. The
practitioner or the patient return the questionnaire with the answers to our
department. If recurrence is suspected we take a biopsy.

22. When follow-up is closed for an individual patient, the reason is recorded:

1. Planned end of follow-up after 48 months.

2. Patient has moved.

3. Death (date of death).

4. Consent withdrawn.

5. Patient has become meanwhile so ill or high-maintenance that no more follow-up
visits can be planned.

6. Recurrence of all of the patient's BCCs.

23. Statistic evaluation is based on an intention-to-treat-analysis.

24. The trial is designed to prove the equivalence of treatment modalities. A statistic
test is used for evaluation, including the Kaplan-Meier-method. When all 4 study arms
contain 116 BCCs, a 2-group-test on the equivalence of ratios with a 1-sided
significance level of 0.05 will have a power of 80% to disprove the null hypothesis.
The null hypothesis is that standard and test method are not equivalent (ratio
difference delta T - delta S ≥ 0.15). Then the alternative hypothesis is more probable,
meaning that the ratios in both groups are equivalent supposed that the expected ratio
difference is 0.07 and the ratio within the standard group is 0.03 (according to an
expected recurrence rate of 3% in the surgical excision study arm).