Oncoplastic breast-conserving surgery

Introduction

The evidence supporting breast conserving surgery is a better option than mastectomy (with or without reconstruction) for those who are suitable is compelling. As such, every effort should be made to offer it. Whilst simple wide local excision for small breast cancers is a routine operation with few technical challenges, for anything slightly larger, many surgeons find it difficult to achieve good cosmetic outcomes, often preferring to perform a mastectomy rather than a cosmetically unacceptable breast-conserving operation. Sometimes this practice extends to performing bilateral mastectomy, which may be an easier way of achieving symmetry and of obtaining a good overall cosmetic result compared to unilateral reconstruction. However, oncoplastic breast-conserving surgery offers a better alternative because it involves a more cost effective surgical approach, better cosmesis and quality of life, a quicker recovery and less risk of complications or future revision procedures.

What about oncological outcomes?

The randomised trials of breast-conserving surgery (BCS) versus mastectomy conducted in the 1980s are still relied on by many as the best evidence of the safety of BCS and these are often quoted as showing that survival is equivalent for these two surgical options but that local recurrence is higher for BCS. However, modern treatment of breast cancer has little in common with treatment of 30–40 years ago. In particular, advances in systemic therapy, neoadjuvant therapy, preoperative investigation and case selection have transformed treatment algorithms and as a result, local recurrence after BCS is now a rare event.

More recent observational studies have shown better survival for breast-conserving therapy than for mastectomy. A study from the Netherlands Cancer Registry, that included all patients diagnosed with cancer from 1989 forward compared 10-year overall survival rates for 37 207 patients after either breast-conserving therapy (BCS) or mastectomy showed that women treated by BCS with lumpectomy and radiation did significantly better regardless of stage at diagnosis, with a 20% increase in overall survival compared to mastectomy. In addition, observational studies on BCS after neoadjuvant therapy for cancers previously thought to be too large for breast conservation show that the local recurrence in this group is lower than the group selected for mastectomy ^, (for further discussion see Chapter 7 ).

Selection bias and radiotherapy administration are likely to partly explain these results. However, this merely reflects that in modern practice selection of the most appropriate treatment for the patient works well. A mastectomy is recommended for certain indications such as extensive disease, genetic predisposition and failure of a patient with a large cancer to respond to neoadjuvant therapy. If these factors are not present, then the choice between mastectomy and breast conservation is not an equal one; it favours breast conservation.

However, there is little to be achieved by performing a breast-conserving operation that results in a poor aesthetic outcome. Extending the option of breast conservation, with its benefits, to all women who do not need a mastectomy requires a skill set in the techniques of oncoplastic BCS.

Oncoplastic BCS also aims to achieve clear margins of excision at one operation. It does this by allowing larger excisions to be taken with no cosmetic penalty. This contrasts with standard BCS that relies on small excisions as the main strategy to achieve minimal impact on cosmesis. Such surgery results in a second therapeutic operation rate of 20–25% with an even higher rate of 30% for DCIS. ^, It is also higher for young women. Oncoplastic surgery aims to reduce the rate of re-excision to less than 10%.

Selection of cases for oncoplastic breast-conserving surgery

It can be argued that all breast surgery should be sympathetic to oncoplastic principles. For oncoplastic BCS specifically, there are some women who are likely to benefit more than others, such as:

• Those with large tumour:breast ratios

  • > 5–10% superiorly, medially or inferiorly

  • > 10–20% laterally

• Those who are at risk of margin involvement

  • DCIS – with or without invasive disease

  • Invasive lobular cancer

  • Women of young age

  • Large tumour size

• Those who are at high risk of a poor outcome with mastectomy and reconstruction because of:

  • Need for radiotherapy after mastectomy

  • Large body mass index (BMI)

  • Need for axillary node clearance

  • No good or acceptable reconstructive option.

Causes of deformity after breast-conserving surgery

All surgery to the breast parenchyma causes scarring and, to some extent, fat necrosis, which occurs when fat and parenchymal tissue is traumatised or loses adequate blood supply resulting in scarring and contraction. Most deformity in BCS is caused by collapse and contraction of the excision cavity and/or unnecessary skin removal and/or poor scar placement or orientation. Radiotherapy, by inducing fibrosis, usually compounds the effects of surgery, and a radiotherapy boost will compound this further. A contracting excision defect will have different effects on cosmesis in different breasts and in different locations within the breast. This will also vary by the size of the defect, mobility and quality of surrounding parenchymal tissue, and elasticity of the skin. Hence an inferior pole excision risks collapse and scarring of the lower pole, pulling down of the nipple and a classic ‘polybeak’ deformity. Likewise, a superior cavity will pull the nipple upwards and a lateral cavity will pull it laterally. Incision scars tend to contract along their length and can accentuate these deformities if not orientated correctly. Hence, a transverse scar placed inferiorly, below the nipple will result in further contraction of the lower pole of the breast and more ‘beaking’ of the nipple, and transverse lateral scars will tend to cause more lateral nipple deviation.

The high-risk areas prone to deformity are those that do not have adequate local tissue to compensate for a collapsing cavity without significant local effect. The breast has considerably more mobility and volume in the lateral half of the breast compared to the medial half. It is for this reason lateral tumour excisions are better tolerated. By contrast, superior and medial locations have less volume and little mobility and are high-risk areas for deformity even if only 5–10% of the breast is removed. Central and inferior excisions are also high-risk for deformity because of significant nipple–areolar complex (NAC) deformity or the dynamics of the polybeak deformity in lower pole tumours.

Other factors are size of the excision in relation to the size of the breast and the quality of the breast tissue. Very glandular, elastic breast tissue will not collapse easily, and is very tolerant of mobilisation, while very fatty breast tissue is more prone to fat necrosis and scarring and is not suitable for mobilisation. Glandular density can be evaluated both clinically and radiographically. Although mammographic evaluation gives a strong indication of what quality of tissue is likely to be found at surgery, clinical assessment both pre- and intraoperatively is essential. Breast density predicts the amount of fat in the breast and determines the ability to perform extensive breast undermining and reshaping without complications, and when it should be avoided. Mammographic breast density can be classified into four categories based on the Breast Imaging Reporting and Data System (BI-RADS). The four categories comprise: (1) fatty; (2) scattered fibroglandular; (3) heterogeneously dense; or (4) extremely dense breast tissue. These categories loosely translate into surgically relevant categories. A dense glandular breast (BI-RADS 3/4) is more forgiving and can be mobilised easily with undermining and advancement of breast tissue into the excision cavity without risk of necrosis. Some oncoplastic techniques described in Asian women, for instance, are only possible because of the dense nature of such breasts. Low-density breast tissue with a major fatty component (BI-RADS 1/2) has a much higher risk of fat necrosis if extensive undermining is performed. Undermining such a breast from both the skin and pectoralis fascia can result in large volume fat necrosis with resulting deformity.

Oncoplastic techniques in breast-conserving surgery

There are both simple and complex oncoplastic techniques. Which to use will depend principally on patient factors and the degree to which a surgeon is comfortable with the technical skills required. As a range of options exists, the adage that ‘the best technique is the one the surgeon is best at’ probably does hold true and the advantages of oncoplastic surgery will be lost if the technical parts of the operation are not executed well. Surgeons should therefore be aware of the options available, offer those within their ability, learn techniques that can extend their practice, and recognise indications to refer to those with more expertise or work in conjunction with surgeons that offer additional skills.

Broadly, oncoplastic procedures can be divided into those that require basic tissue handling skills and follow a simple template, and those that are more creative and require expertise in cosmetic surgery techniques and flaps. Both approaches can significantly extend the role and outcome of BCS and surgeons do not need to be able to perform all, but should aspire to be competent in as many techniques as possible. In a similar vein, oncoplastic techniques are often referred to as Level I or II procedures, as has been championed by Clough. Level I procedures have been described as those that allow up to 20% of breast volume to be excised, especially in the lateral breast. Level II covers more complex mammaplasty procedures, and within this category we would also include volume-replacement techniques.

In practice, there are a spectrum of techniques that can be employed and there is an overlap in the indications. For instance, is an upper pole tumour in a moderate breast with slight ptosis better treated with simple skin undermining, a round block rotation or a therapeutic mammaplasty? Of course, the answer depends on breast morphology, parenchymal type, patient preference and surgical expertise. In different surgeons’ hands it may be any of the above options. The philosophy of ‘keeping it simple’ in terms of applying simple or Level I techniques to the majority (85–90%) of cancers is appealing and makes sense. However, a more technically demanding procedure may often be less disruptive, and incur a much smaller risk of fat necrosis, deformity or requirement for further surgery. Whatever is offered, the procedure should be low risk, and performed (patient factors permitting) as a day case procedure.

Important principles of oncoplastic BCS include the following:

• Maintain breast form and shape – sometimes keeping a normal-looking breast on the cancer side may be at the expense of overall symmetry.

• Perform the simplest procedure that gives an acceptable result.

• Only perform techniques within your own skill set.

• Do not compromise on the wide local excision to facilitate better cosmesis.

• Choose safety over perfect cosmesis – for some women a safer procedure that means accepting a small deformity, asymmetry or less than perfect appearance is still a much better option than the alternatives.

• Aim for all necessary surgery to be completed at one operation (including symmetrisation if required).

Volume displacement or replacement?

Confining surgery to within the breast is usually easier. It limits all scars to the breast and avoids donor site problems. As such, volume displacement should usually be considered as the default choice. Volume replacement surgery is predominantly indicated in the smaller non-ptotic breast in which volume displacement options are limited.

Timing of oncoplastic breast surgery

In general, it is far better to avoid deformity rather than try to correct later. Oncoplastic procedures should therefore be planned and performed at the same time as the primary breast cancer surgery. Exceptions to this may be in volume replacement techniques using thoracodorsal pedicles or possibly free flaps, when achieving certainty of clear margins may be sensible before committing to that option.

With regards to the timing of any contralateral symmetrising surgery that is planned, it is usually more appropriate to do the symmetrisation immediately. Delayed symmetrisation is not easier or more likely to achieve better symmetry and leaving patients asymmetrical even for a short time is not necessary.

Basic techniques in breast-conserving surgery

In most simple BCS cases, minimising the cavity size will maximise outcome. It is for this reason cancer excisions should be planned accurately with appropriate width of clear margins and avoidance of unnecessary tissue excision, whilst not compromising on excising what is necessary. Releasing the breast in the subcutaneous plane from the skin will increase parenchymal mobility and allow the tissue to ‘fall’ into the tumour cavity. The other option is to release parenchymal tissue from the chest wall. Ultimate freedom is created by doing both. However, parenchymal flaps released from both the skin and chest wall are at higher risk of fat necrosis, especially in the fatty breast. Although not always feasible, moving breast tissue is best done when it is left attached to either the chest wall or the skin (this can include de-epithelialised skin). However, excessive undermining will produce internal scarring and some fat necrosis and there soon comes a point at which more formal oncoplastic techniques become indicated.

As a principle, it is important to encourage the tumour cavity to collapse in a planned orientation to minimise deformity. Usually the cavity should be designed to collapse in a radial direction around the NAC ( Fig. 8.1 ). For example, in the inferior pole the cavity should collapse in a vertical orientation and a 9 o’clock tumour in a horizontal direction. This principle will minimise NAC movement and any skin or parenchymal undermining should be done to encourage this.

Round block and tennis racket techniques

The round block mammaplasty was originally described by Benelli. The procedure starts by making two concentric periareolar incisions, followed by de-epithelialisation of the intervening skin. The outer edge of de-epithelialised skin is incised and the entire skin envelope can then be undermined to allow access to the tumour. The NAC remains vascularised through its posterior glandular base. Resection of the lesion from the subcutaneous tissue down to the pectoralis fascia is performed. The breast flaps are then mobilised off the pectoralis fascia and advanced towards each other to eliminate the excision defect. The outer skin incision is then purse-stringed and the two skin incisions then approximated, resulting in a circumareolar scar.

Clough describes six steps for level I oncoplastic surgery that begin with the skin incision (1) followed by undermining of the skin (2) and NAC (3). After completion of undermining, a full-thickness glandular excision incorporating the cancer and a surrounding rim of normal breast tissue is performed from subcutaneous fat down to pectoralis fascia (4). The glandular defect is subsequently closed, following specimen X-ray to demonstrate complete radiological excision, with tissue re-approximation (5). If required, an area in the shape of a crescent bordering the areola is de-epithelialised to reposition the NAC (6). If this is not performed the NAC often displaces towards the site of excision. (See Figs. 8.2 and 8.3 .)

Incisions

An oncoplastic approach includes choosing an appropriate scar position and orientation. Good principles of scar healing include placing them where possible along the lines of skin tension (see Chapter 7 on breast-conserving surgery) and minimising tension of closure. Shorter scars are not always less visible or a particularly good strategy to achieve good cosmesis and many oncoplastic procedures produce long scars to achieve both tumour excision and breast reshaping.

Dynamic tension lines over the breast vary according to breast shape (particularly the degree of ptosis) and skin elasticity (usually related to age). In general, scars concentric to the NAC rarely follow tension lines other than in firm, non-glandular breasts. By contrast, tension lines are often orientated towards the NAC in the lateral and medial parts of the breast, and in the upper and lower part of the breast tension lines are usually transverse. Placing incisions in tension lines facilitates good healing and hence a good cosmetic appearance. However, in the lower pole of the breast, vertical incisions, which may be perpendicular to tension lines, heal very well because the dynamic forces on the resulting scar (weight of the breast) act along its length ( Fig. 8.4 ).

Whilst poor incision placement can compound the forces that produce deformity after BCS, good incision placement will only aid cosmesis if the underlying breast excision is closed appropriately and this is usually in a radial direction around the NAC. It is often useful to place a tension line incision a little inferior to the tumour and close the defect above it. Thus, the incision is well supported by underlying tissue, rather than being affected by a healing and contracting cavity. The only reason to place an incision directly over a cancer is if skin is to be removed over it, which is only necessary if it is directly involved. Skin closure should be layered with everting deep dermal sutures, anticipating that the scar will tend to invert.

Periareolar scars usually give good access to much of the upper half of the breast and are the standard approach in round block techniques. Again, there is a balance between excessive undermining and using a simple tension line incision just below the tumour or a different oncoplastic approach. A periareolar incision for a high upper pole lesion can require extensive skin undermining for access, the scarring from which will contract and pull the nipple upwards so the nipple needs to be disconnected from the underlying breast tissue and re centralized to stop this happening.

Direct oncoplastic excisions with centralisation of NAC

Direct excisions (en bloc skin and wide local excision) are helpful in that they minimise undermining and mobilisation of breast tissue. As such, they require less expertise in mammaplasty surgery. For surgeons without such knowledge these are lower-risk procedures and, to a degree, very reproducible. Sometimes referred to as ‘tennis racket techniques’, they allow closure of the tumour cavity radial to the nipple and centralisation of the NAC position ( Fig. 8.5 ). As such, they achieve many of the oncoplastic principles of reducing the negative impact of BCS. The main reason for excision over the tumour is to simplify the technique, although occasionally it is oncologically indicated. After wide excision, the reshaping is performed by mobilising the glandular tissue either side of the defect into the cavity and suturing it together. The NAC is then centralised with de-epithelialisation to the required location. The disadvantage of this approach is that up to half of the volume of excision may be skin and subcutaneous fat and this volume would not need to be excised if a remote scar is used. Alternatively, complete detachment of the retroareolar gland from the NAC enables the central part of the gland to be available for volume redistribution without compromise of NAC vascularity. Once the defect is eliminated, the NAC is placed in its optimal position, at the centre of the new breast mound. Such techniques are also helpful in all patients at higher risk of fat necrosis – smokers, diabetics, and can be considered in obese patients.

Another direct excision option is the ‘batwing mammaplasty’, as described by Silverstein (see Fig. 8.6 ). This allows similar principles to be applied for tumours above the NAC or in a lateral or medial location. Although this can elevate the nipple, it does not address the main issue in larger breasts with ptosis, namely the excess skin and glandular tissue below the nipple and the large areola to inframammary fold distance. For this reason, it is not a widely used technique.