A View of Breast Cancer Today

The incidence of breast cancer has shown a steady increase since 1930. Coincident with this fact is a wider compliance of American women with recommended screening guidelines for mammography. The result of this has been the earlier detection of more breast cancers. Indeed, an NIH Conference Statement said that three-fourths of such cases would be eligible for conservative treatment. As an aside, an update in screening criteria is presented elsewhere in this issue.

Relative to all of the above, there is also a growing demand in our society for improved quality of life in cancer treatment. And in the situation of early breast cancer, this does quite simply equate to breast conservation (avoiding mastectomy).

In this context, this presentation will be limited to the circumstances of early disease, amenable to a local surgical procedure, and generally to be followed by radiation therapy which is both prophylactic and therapeutic. To support this approach, many studies have shown multiple foci of microscopic cancer in the breast distant to the primary tumor site. Further, other studies have shown a significant decrease in the incidence of recurrence when radiation has been given. In one collation of data, the group without radiation had a breast recurrence rate of 29% to 39%, whereas the group with radiation had a lesser recurrence rate of 10% to 14%.

The Ideal Patient

Criteria relating to the selection of patients could lead to an extensive discussion which is beyond the scope of this presentation. Thus, for simplicity, the ideal patient for this technique would present in this fashion:

1. Small primary tumor (less than 5 cm.).
2. No positive nodes (from axillary sampling).
3. Well-differentiated histology, low nuclear grade.
4. No vascular or lymphatic invasion.
5. Solitary primary lesion.
6. Positive estrogen and progesterone receptors.

Degrees of deviation from the above criteria would appropriately lead to a consideration of adjuvant chemotheraphy.

Surgery

This subject is discussed more fully elsewhere in this issue. However, related to radiation therapy, two comments deserve space. First, the radiation treatment can and should commence two to four weeks after surgery is completed. Secondly, the placement of metallic clips to show resection margins and depth is helpful in planning and delivering the radiation boost dose.

Radiation Therapy

This technique is generally simple and uncomplicated. Basically, the entire breast is encompassed by opposed tangential ports across the chest wall.

Most commonly, a medium energy photon beam is utilized to treat the entire breast. Such an energy can be provided by the Cobalt-60 apparatus or by a Linear Accelerator generating energies of 4MV to 6MV. A minimal dose of 4500 to 5000 rad is delivered in a span of 5 to 6 weeks. This is generally followed by a boost to the local tumor site. This is now most commonly done utilizing an electron bean of 9 to 12 MV, and delivering an additional 1000 to 1500 rad in about 1 ½ weeks. The above treatment protocol will require a total of six to seven weeks to complete. Morbidity is minimal. Generally, there are no systemic symptoms such a radiation sickness. Also, skin reactions are minimal, presenting as a mild tanning in most individuals to a moderate erythema in the fair-skinned. Post-treatment fibrosis with pain is rare. In this author's experience, these patients are pleased with having elected this treatment option, both immediately and long term.

Long Term Survival

With the passage of time, meaningful survival information has been accumulated. A recent analysis of this group of patients entered into all trials before 1985, comparing mastectomy with conservative surgery and radiation, showed no difference in survival.

Conclusion

At this point in time, it can be stated that properly selected cases of local breast cancer can be appropriately and safely treated for cure by a combination of conservative therapy and radiation therapy.

References

1. Cox, JD: Moss' Radiation Oncology, 7^th edition, Mosby-Year Book, Inc. 1994
2. Perez, CA and Brady, LB: Principles and Practice of Radiation Oncology, 2^nd edition, J.B. Lippincott Co., 1992
3. Levitt, SH, Khan, FM, Potish, RA: Levitt and Tapley's Technological Basis of Radiation Therapy, 2^nd edition, Lea & Febiger, 1992
4. Kumar, PP: Radiation Therapy, University of Nebraska Medical Center, 1992

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