Total mastectomy in  "in situ" carcinoma of the breast:
surgey of choice or the only possibility ?

Autori: A. Lucchini, S. Passerini, P. P. Puviani, G. L. Liera, 
F. Pirondi, A. Savioli, M. Franzini

Ospedale Comprensoriale di Guastalla (Reggio Emilia)
Divisione di Chirurgia Generale
Primario: Dr. M. Franzini

SUMMARY

The increased use of conservative surgery to treat infiltrating breast cancer at T1 stage and the progressive increase of "in situ" carcinomas which are brought to the attention of surgeons, has cast some doubt on the legitimacy of systemic recourse to total mastectomy for this latter group of breast cancers.
We offer the results obtained in our Division over the past five years as a starting out point for reflection.

INTRODUCTION

"In situ" carcinomas (ISC) of the breast are defined as neoplasms in which the proliferation of malign epitelial cells occurs inside the ducts (ISDC) or inside the terminal part of the glandular lobules (ISLC) without invading the glandular stroma (1).
As a matter of fact, studies made with the electronic microscope have shown breaks in the basal membrane which were not highlighted by the normal optical microscope.
However, this did not necessarily involve an aggressive potential (1,5). Thus, by definition, they are biologically less aggressive neoplasms than infiltrating carcinomas.
Relatively few in number up to about 15 years ago, they were treated with the same procedure as any other breast tumor, i. e. with total mastectomy.
The widespread use of mammographic screening in patients over 40 and the subsequent revelation of infraclinic lesions, has almost quadrupled the number of cases of ISC discovered.
In recent case studies, ISC accounted for 15-20% of all breast carcinomas (3,5).
This evidence of a constantly increasing number of cases and the introduction of conservative surgery to treat infiltrating stage T1 breast carcinomas has made the choice of therapy for the treatment of ISC extremely important.
Total mastectomy, still today the treatment of choice for ISDC according to the FONCAM protocol, is no longer considered by numerous Authors (5,6,7,8) as always essential for neoplasms which are often much smaller and less aggressive than infiltrating carcinomas and whose multiplicity of foci is often highlighted by mammography.
These same Authors believe that careful radiological, clinical and histopathological examination, bearing in mind histological subtype and any areas of microinfiltration, allows cases of ISC to be identified in which conservative surgical procedures can be beneficial without any necessary additional radiation therapy.
The published case studies, in this context, are comforting. However essential control clinical studies are so far missing and it is these which will generate the definitive proof of the usefulness of this therapeutic direction.
The purpose of this present study is to evaluate the results obtained in our Division and to offer them as further food for thought.
And this despite our full awareness of the smallness of the sampling and the shortness of the follow up which combine to make them statistically unassayable.

MATERIAL AND METHODS

Between 1983 and 1988 we observed 22 cases of breast ISC out of a total of 270 breast neoplasms. The average age was 56 and the range was from 25 to 79. In 12 cases (55%) the suspicion of ISC stemmed from mammography; in 7 cases (32%) by the clinical discovery of a neoformation and in 3 cases (13%) by secretion from the nipple.
In 18 cases the histotype was ISDC and in 4 cases ISLC, with ratio of 4.5:1.
Histological examination of frozen sections confirmed the difficulty of reaching a correct diagnosis (3). In fact microinfiltration outbreaks were highlighted in 4 cases but only when the frozen sections were examined.
Sixteen quadrantectomies with lymph gland dissection at the 1st and 2nd axillary level and 6 mastectomies with the Madden modification were performed.
This latter operation was used for 2 patients whose neoformation was over 3 cm in diameter and showed microinfiltration foci at the histological examination. It was also used on 4 patients where the mammography showed suspicious nests of microcalcification in more than one quadrant.
The axillary lymph nodes were positive in only one patient subjected to mastectomy for a 3 cm ISDC with invasive microfoci.

RESULTS AND CONCLUSIONS

All the patients were followed up with an annual mammography and quarterly clinical check ups. We noted just a single relapse (6.25%) in the quadrantectomy group during the observation period.
The relapse appeared 18 months after the operation for a 2 cm diameter ISDC. Two patients at 36 and 43 months developed a neoplasm in the controlateral breast.
Both were ductal infiltrating carcinomas, while the first neoplasms were a ISLC and a ISDC. Both patients were given a quadrantectomy and complementary radiation therapy.
No neoplastic progression was noted.
ISC therapy had undoubtedly been negatively affected by the fact that up to 15 years or so ago, its incidence in the literature as a percentage was fairly low and thus little attention was given to it in studies on breast cancer.
However we should point out that the basic problem has still to be answered, i. e. are ISC preinvasive neoplasms destined to evolve clinically into more aggressive tumors or should they be regarded merely indicating the risk of development of invasive carcinomas?
At the current state of our knowledge we can only affirm that:
  1. ISDC is undoubtedly more frequent than ISLC;
  2. ISLC is often characterized by a multiplicity of foci and bilaterality and is frequently associated with a subsequent invasive carcinoma of the breast or of the controlateral breast;
  3. ISDC, on the other hand, involves a single quadrant and can be associated with a subsequent homolateral infiltrating carcinoma in the same quadrant originally involved with the ISDC (2,3,4);
  4. in ISDC the frequency of infiltration microfoci, highlighted by the electronic microscope, increases the possibility of lymph gland metastasizing.
On the basis of the case studies reported in the literature and above all, taking into account the possibility of performing conservative surgery as in T1 stage ductal infiltrating carcinoma, systematic recourse to mastectomy no longer seems justifiable in all cases of ISDC.
In fact, in ISDC with a diameter of over 3 cm where frequently foci of microinfiltration are highlighted, total mastectomy with lymph gland dissection is undoubtedly necessary.
For the same reason, if in ISDC mammography shows nests of microcalcification in a number of quadrants, total mastectomy should certainly be used because of the polycentricity.
On the other hand, we feel that small size ISDC where the X-ray examination shows a single focus and where there are no micro-breaks in the basal membrane, can be treated with conservative surgery, i. e. with quadrantectomy and complementary radiation therapy.
These conclusions, supported by the results reported in the literature, have induced us to use a conservational therapy with complementary radiation therapy for "in situ" ductal carcinomas.
The results obtained, though the case study is limited in number and the follow up period still relatively short, are encouraging.
However only controlled clinical studies will be able to demonstrate the true reliability of this therapeutic approach.

REFERENCES
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  3. COOKE T. G.: Ductal carcinoma in situ: a new clinical problem. Br. J. Surg., 76: 660-662, 1989.
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